Research On Ferrocement - Global Perspective
Research On Ferrocement - Global Perspective
Research On Ferrocement - Global Perspective
j
JOU NAL CF
FERRDCEMENT~
APR 05 1991
JOURNAL OF
FERROCEMENT
Abstracted in: Cambridge Scientific Abstract; USSRs Referativni Zhumal; ACI Concrete Abstracts;
Engineered Materials Abstracts; International Civil Engineering Abstracts.
Reviewed in: Applied Mechanics Review
EDITORIAL STAFF
EDITORIAL BOARD
Mr. D.J. Alexander Alexander and Associates, Consulting Engineering, Auckland, New Zealand.
Professor A.R. Cusens Head, Department of Civil Engineering, University of Leeds, Leeds LS2 9JT,
England, U.K.
Mr. J. Fyson Fishery Industry Officer (Vessels), Fish Production and Marketing Service, UN-
FAO, Rome, Italy.
Mr. M.E.loms Ferrocement International Co., 1512 Lakewood Drive, West Sacramento, CA 95691,
U.S.A.
Professor A.E. Naaman Department of Civil Engineering, The University of Michigan, 304 West Engineering
Building, Ann Arbor, MI 48109-1092, U.S.A.
Professor J.P. Romualdi Professor of Civil Engineering, Carnegie-Mellon University, Pittsburg,
Pennsylvania, U.S.A.
Professor S.P. Shah Department of Civil Engineering, Northwestern University, Evanston, Illinois
60201, U.S.A.
Professor D.N. Trikha Professor of Civil Engineering, University of Roorkee, Roorkee, U.P., India.
Professor B.R. Walkus Department of Civil Engineering, Technical University of Czestochowa
Malchowskiego 80, 90-159 Lodz, Poland.
CORRESPONDENTS
Mr. D.P. Barnard Director, New Zealand Concrete Research Association, Private Bag, Porirua, New
Zealand.
Dr. G.L. Bowen P.O. Box 2311, Sitka, Alaska 99835, U.S.A.
Dr. M.D. Daulat Hussain Associate Professor, Faculty of Agricultural Engineering, Bangladesh Agricultural
University, Mymensingh, Bangladesh.
Mr. Lawrence Mahan 737 Race Lane, R.F.D. No. 1, Marstons Mills, Mass. 02648, U.S.A.
Mr. Prem Chandra Sharma Scientist and Project Leader, Drinking Water Project Mission Project, Structural
Engineering Research Centre, Sector 19, Central Government, Enclare Kamla Nehru
Nagu Ghaziabad, U.P., India.
Dr. B.V. Subrahmanyam Chief Executive, Dr. BVS Consultants, 76 Third Cross StreetRaghava Reddy Colony,
Madras 600 095, India.
Mr. S.A. Qadeer Managing Director, Safety Sealers (Eastern) Ltd., P.O. Box No. 8048, Karachi, 29
Pakistan.
.Lo
~ro
The Editor
iii
Journal of Ferroeemenl: Vol. 20, No. 4, October 1990 349
A simple analytical Tn()del is proposed lo study the ductility offerrocemenl subjected lo flexural
loading. The curvatures al failure, obtained using the Tn()del are compared with experimental
results. A parametric study was conducted lo estimate the influence of: volume fraction of
reinforcement, type of distribution of reinforcement, fracture strain of reinforcement and the
thickness of the beam. The results indicate that fracture strain, and thickness of the beam affect the
curvature at failure (or ductility) Tri() re than the other variables.
INTRODUCTION
The strength aspect of ferrocement beams have been studied by a number of investigators (1-4 ).
The general consensus is that ferrocement beams can be treated similar to reinforced concrete beams
for strength evaluation. The ductility aspect of ferrocement beams has been studied only to a limited
extent, even though ductility is extremely important in failures caused by impact and earthquake
type (low cycle high amplitude) loads. In certain field applications ferrocement could be subjected
to aforementioned type of loads. This paper provides some insight regarding the ductility of
ferrocement subjected to flexural loading.
A simple model is proposed to evaluate the curvature at failure, ~u' which is an indicator of
ductility. The results obtained using the model are compared with the experimental results. The
model is also used to perform a parametric study involving the variables that affect the ductility.
The proposed model is based on an assumption that the beam failure occurs when the strain in
extreme tension layer reinforcement reaches its fracture strain. The other possible modes of failure
are: by crushing of concrete, or by failure of compression steel. Fracture strain of steel is much
higher than crushing strain of concrete and hence failure of compression steel is not possible before
crushing of concrete. Since most ferrocement beams contain equal amount of compression and
tension steel, in most if not all cases, failure occurs by fracture of tension steel. Therefore, in all
cases, the failure mode is assumed to be by fracture of extreme tension layer steel. The maximum
sµ-ains in mortar at failure seem to be around 0.004 mm/mm, supporting the above hypothesis.
The model is also based on the following well established assumptions:
* The contribution of mortar in the compression zone can be represented by an equivalent
rectangular stress block.
t Reprinted with permission from Ferrocement : Applications and Progress, Proceedings of the 1bird International
Symposiwn on Ferrocement (8-10 December 1988), Roorkee, India
• Professor of Civil Engineering, Rutgers, The State University, New Jersey, U.S.A.
" Professor of Civil Engineering, Northwestern University, Illinois, U.S.A.
• Graduate Student, Department of Civil Engineering, Rutgers, The State University, New Jersey, U.S.A.
350 Jo11rnal of Ferrocemi!nl: Vol. 20, No. 4, October 1990
START
Adjust No----£
N.A. C
Yes
STOP
Fig. l. Flow chart of sequence of calculations for computing moment and curvature at failure.
,
Journal of Ferrocement: Vol. 20, No. 4, October 1990 351
type of manufacture and type of cut (i.e., parallel or perpendicular to the wire mesh roll) [5]. The
authors recommend an average value of 0.015 mm/mm for wire meshes cut longitudinally, with
wire spacing of 13 mm or higher. For 6mm wire spacing 0.010 mm/mm seem to be more appropri-
ate.
* Assume a depth of neutral axis, c. Using a linear strain distribution, the fracture strain, E
and c, compute the strains, stresses and forces in various layers of wire reinforcement and the force
contribution of matrix. In most cases the strain in the extreme compression layer will be greater than
0.002 mm/mm and hence rectangular stress block assumption can be used for computing compres-
sive force contribution of mortar. However if the strains are less than 0.0015mm/mm the behaviour
of mortar might have to be assumed as linearly elastic, resulting in the triangular stress distribution.
After computing the forces in the reinforcement layers and mortar, compare the compression
and tension forces for equilibrium. If they are not equal, adjust the depth of neutral axis, up or down,
to obtain the force equilibrium.
* Use the depth of neutral axis at equilibrium to compute the forces and moments.
* The curvature at failure,<!>. can be written as: (Fig.2.)
f--- b - - ~-----1 ft
Cross section Strain Mortar Reinforcement
diagram
stress and force diagrams
- £.ii
<!>u-- (1)
C
where Ecu is the strain in the extreme compression layer and c is the depth of neutral axis
Note that the strain E is computed using an assumed fracture strain, E at the extreme tension
~ cu w
The model was evaluated using the experimental results. The following are the pertinent
details of the experimental program.
Number of specimens and details: five beams with 4, 6, 8, 12 and 20 layers of steel with beam
thickness 20 mm, 40 mm, 60 mm, 80 mm and 100 mm respectively for welded wire mesh (wire and
spacing 12.7 mm) and five beams with 6, 9, 12, 18 and 30 layers of steel with beam thickness
20 mm, 40 mm, 60 mm, 80 mm and 100 mm respectively for wovem wire mesh (wire spacing
8.Smm).
Cube strength of mortar: 29.9 MPa.
352 Journal of Ferrocement: Vol. 20, No. 4, October 1990
Young's modulus of wire mesh: 2 x 1()5 MPa for welded mesh, 1.38 x 1()5 MPa for woven mesh.
Yield strength of wire mesh: 410 MPa for welded mesh and 385 MPa for woven mesh.
Using a computer program developed, based on the algorithm presented in the previous
section, all the beams were analyzed to obtain the ultimate moment and the curvature at failure, <I> •
The computed and experimental curvatures are compared in Fig.3. Based on the results reported by
Nanni and Zollo [5], fracture strains of 0.02 mm/mm and O.oI mm/mm were assumed for half
welded (wire spacing 12.7 mm) and quarter woven (wire spacing 8.5 mm) meshes respectively. It
can be seen from Fig.3, that the model provides acceptable results. Once the model was validated, a
parametric study was conducted to evaluate the influence of various parameters on ductility.
The authors would like to note that a more accurate analysis could be done using the experi-
mental stress-strain curves of mortar and steel meshes, based on the strength model presented in
Ref.2.
• - Welded mesh
t:>. - Woven
•
mesh
1.2
'.'.'.:J45°
1.0
E
~
c 0.8
•
c
'O
~
cu 0.6 •"'
~
cc
<[
. 0.4 • "'
"
6l
• "'
0.2
"'
0u Experimental, radians /m
PARAME1RIC STUDY
The variables investigated in parametric study were: (i) fracture strain of reinforcement, (ii)
beam thickness, (iii) reinforcement ratios, and (iv) type of distribution. The results are presented in
Figs. 4, 5 and 6. The fracture strain was assumed to be 0.015 mm/mm for graps presented in Figs. 5
and6.
The following observations can be made based on Figs. 4, 5 and 6.
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 353
1.2
4 layers (20 WL 4}
1.0
20 mm
E
......
II) Vol. fraction of mesh : 3.62 %
c
:5 0.8
~
:::>
s
~ 0.6
~
:::> Vol. fraction of mesh : 3.62 %
c
~
:::> Beam thickness : 100 mm
(.) 0.4
20 layers ( 100 WL 20)
0.2
mm
25 50 75
0.8
E 0.7
.,c
......
0
'O
~ 0.6
:::>
Q 0.5
~
:::>
c~ 0.4
:::>
u
0.3
0.2
25 50 75
0.8
4 layers
~ 0.7
"'c:
0
6 layers
'O
~ 0.6
0.5
~
:::i
0
~ 0.4
:::i
u
0.3
0.2
CONCLUSIONS
Based on the results of this study, the following conclusions can be drawn.
- The proposed model accurately estimates the curvature at failure and hence the ductility of
ferrocement beams.
- The curvature at failure decreases considerably for thicker beams. Since ferrocement is
normally used in thin sections, ferrocement structural components can be expected to be highly
ductile.
- The other variable that influence ductility considerably is the fracture strain. Reinforcement
ratio (for beams with more than 4 layers) and type of reinforcement distribution affects the ductility
only to a small extent.
REFERENCES
1. ACI Committee 549. 1988. Design, construction and repair of ferrocement. ACI Structural
Journal 85(37):325-351.
Joiunal of Ferrocement: Vol. 20, No. 4, October 1990 355
2. Balaguru, P.; Narunan, A.E.; and Shah, S.P. 1977. Analysis and behavior of ferrocement in
flexure. Proceedings, ASCE Structures Division. 103(10): 1937-1951.
3. Logan, D., and Shah, S.P. 1973. Moment capacity and cracking behavior of ferrocement in
flexure. Journal of ACI 70(21): 799-804
4. Mansur, M.A., and Paramasivam, P.1986. Cracking behavior and ultimate strength of ferroce-
ment in flexure. Journal of Ferrocement 16(4): 405-415.
5. Nanni, A., and Zollo, R.F. 1987. Behavior of ferrocement reinforcement in tension. ACI
Materials Journal. 84(4): 273-277.
JourNJ/ of Ferrocemenl: Vol. 20, No. 4, October 1990 357
Aferrocement door is easy to make, strong and durable, water resistant and requires very little
maintenance. The cost price (labour + materials) for a ferrocement door is approximately
US$10!m2. This can vary from place to place. Auroville Building Centre, a unit of the Centre for
Scientific Research (CSR), has been developing and testing doors made out of ferrocement since
1986. The following document gives a detailed description of the manufacturing process of
ferrocement doors, the materials and tools needed and details for fixing the hinges and locking
arrangement.
IN1RODUCTION
When saving trees becomes an internationally and nationally acclaimed password, looking for
alternatives or substitutes to wood products is as important and necessary as reafforestation or
conserving forests. With the increasing cost price of wood, it will be necessary to come up with
alternatives to wood products (for urban and rural use) in order to ease the pressure on the
remaining tree population and bridge the time gap for new plantations to get established and be in
full commercial operation.
The following two facts illustrate the potential of ferrocement doors:
- While comparing cost figures for standard wooden doors (2.00 m x 0.90 m) for a low-cost
housing scheme executed in our local area, the manufacturing of 2,000 ordinary standard doors in
"country" wood would have cost US$73,300. To manufacture the same number of doors in
ferrocement an amount of US$ 49,300 would be required. Apart from saving US$24,000 and the
saving of about 167 m3 of wood, the beneficiaries would have received a better and durable product
for a lesser price.
- In 1988, according to a senior engineer responsible for the housing facilities of BHEL, a
company in Hyderabad (India), his company spends yearly more than US$80,000 to replace or
maintain the wooden doors and window shutters of the employees' houses. This figure reflects the
huge expenses involved in maintaining wooden doors, frames and windows in many other big
housing complexes.
These two examples, shows the saving that could be made either in production or in mainte-
nance costs by using ferrocement doors. These indicate the real potential of fcrrocement doors as
replacement product for wooden doors. Considering this potential, its is important to identify the
advantages and disadvantages of the use of ferrocement doors.
The advantages of ferrocement doors are:
- The materials required are commonly available.
- Manufacturing techniques can be taught to semi-skilled labor.
- Only manual labor is involved in manufacturing the basic ferrocement door panels.
- Ferrocement doors are strong, durable, fireproof, waterproof, termite resistant and easy to
repair.
- Ferrocement doors can be made on any flat surface with ordinary mason tools and are easy to
transport and install.
- A broken ferrocement door can easily be repaired.
MANUFACTURING PROCESS
Mesh Preparation
1. Use hexagonal 12 mm x 0.71 mm (22 gauge) galvanized iron (GI) "Chicken mesh" as
reinforcement. Use rolls of either 0.90 m or 1.20 m width.
2. With the help of a string dipped in some water based paint, mark the door size on the
casting platform. Take care to obtain right angle comers. (Fig.I)
3. Cut four separate strips of mesh off with a wiremesh cutter to the door size plus 100 mm all
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 359
Fig. I. Marking of the door sire on a casting platform. Fig. 2. Mesh preparation.
t
Fig. 3. Folding of the mesh.
Casting Procedure
1. Oil the portion of the casling platfonn lo be used with a paint brush to ensure easy
dcmoulding. Use waste engine oil for this purpose. (Fig.7).
2. Mix the amount of sand, cement and water on a clean surface nearby or even better in a
mixing val
Mixing ratios are very important and should be strictly followed. The water: cement: sand
(W:C:S) ratio for ferrocement doors is 0.40:1:1.5 by weighL Sand and cement are first evenly
mixed, the required quantity of water is added afterwards. e.g.: for a door of 2.00 m x 0.90 m of
12 mm thickness, the approximate amount of water, cement and sand are 8.1 liter 20.0 kg, and
30.0 kg, (dry), respectively.
3. Spread a fine layer of mortar over the oiled surface. The thickness should not be more
then 5 mm. (Fig.8).
4. Softly press the steclmat onto the spread out mortar layer, care must be taken to posilion it
correctly. Place two wooden or aluminium rulers along the two longest sides of the door to facilitate
the filling up of the second layer of mortar and to stay within the exact dimensions of the door
(Fig.9).
5. Then spread the second and last layer of mortar over the steelmat, using the two rulers as
a guiding level for the appropriate dimensions and also the final thickness of the door. (Fig. 9).
6. Obtain a smooth finish by sprinkling a handful of cement and rubbing it in with a mason's
trowel in a circular manner.
Special care is taken to finish the top, sides and edges of the door neatly (Fig. 10-11). The
average thickness of a ferrocement door should be around 12 mm. The rulers have a similar
dimension which helps in maintaining this thickness. Vibration is not required.
7. Leave the finished door untouched until the next day (about 12 hours). Precaution has to
be taken to make sure that nobody steps on it. If needed, lay a plastic cover over it to give some
protection against the hot sun.
Curing Procedure
- 'I
Fig. 7. Oiling the casting area. Fig. 8. Applying the first mortar layer.
Fig. 9. Placing of the steel mat and applying second mortar layer
362 Journal of F~"octmefll: Vol. 20, No. 4, Octo~r 1990
Since the ferrocement units are usually much thinner than normal concrel.C products, a properly
carried out curing ~edure is even more important.
Curing is the action by which the water trapped in the freshly cast sr:ructure is released slowly
over a period of time. This should take place slowly in order to prevent cracks which would weaken
the product. For this purpose, leave the freshly cast door in place on the casting platform. Then
spread a sand or coirdust layer evenly over the door and sprinkle water several times a day and never
allow to dry out. The sand or coir dust should be kept moist for about 15 to 21 days.
One can also demould from the casting platform aft.er two days and cure elsewhere.
DEMOULDING PROCESS
After a minimum of 20 days, the curing Lime for a ferrocement door is over and the mortar
mixture has attained its full sr:ructural strength.
For demoulding the ferrocemcnt door, carefully insert a large mason's trowel under one of the
long sides of the door and move it slowly under the whole length of the door to separal.C the
ferrocement plate softly from the casting platform. The oil ensures that no bond has taken place
with the mortar during the casting and curing period.
Once the ferrocement door panel is loosened, two or three person could quickly lift it up on
one of its long sides (Fig.13). The door is now ready for the filling and locks.
Use 300 mm to 460 mm (18 in.) steel T-hinges, tower bolts, aldrops and rim locks. For a door
of 2.00 m x 0.90 m, use three T-hinges of 460 mm (18 in.) to hang the door dircclly on to a brickwall,
a pillar or even a wooden frame. The holes should be premarked for hinges and locks. Use an
electric power drill with a small diameter masonry drill bit to drill the required holes. Afterwards
use a bigger size masonry drill to enlarge the holes to the required size (Fig.14). Attach the three
hinges with bolts, nuts and washers. Fit tower bolts, aldrops and rim locks in the same way.
For making a keyhole several holes are drilled next to each other until the appropriate size for
the key hole is obtained.
Fig. 10. Striking off the excess mon.ar. Fig. 11. F"utlshing the ferrocement door edges and polishing
the surface area.
Fig. 14. Fixing the door hinges. Fig. 13. Lifting the door panel off the casting platform.
364 /011Tnal of Fe"ocUNnl: Vol. 20, No. 4, Oc1ober 1990
If breakage occws, repair the ferrocement door by removing cement around the cracks. Then
clean the exposed wiremesh properly with a wire brush and place the door on a Oat surface, then
cement the cracks with normal mortar mixture.
Cu.re the repaired section for the required number of days. A repaired ferrocement door is as
strong as the original one.
Thickness minimum = 8 mm
maximum = 12 mm
Labor
Preparation of
steel mat I bar bender + 1 helper : 2 hour/m1 •
Casting 1 mason +I helper : 2 hour/m1.
Total 1 mason + 1 helper : 4 hour/m2•
The construction technique discussed is for the most simple form of ferrocement doors
(Table 1). Once this technique is mastered, several improvements can be undertaken such as:
- Commercial plasticizer can be used to augment the workability of the mortar mix and to
reduce the water content thus enhancing the mortar strength.
- Do away with visible hinges. A technique for incorporating plate hinges in the ferrocement
door was developed at the Auroville Building Centre.
- If a micro-enterprise is envisaged in the manufacture of ferrocement doors, speed up produc-
JowMl of Fe"ocemznJ: Vol. 20, No. 4, October 1990 365
lion by using a plate vibraior IO casL Lhe doors. This would reduce the manufacturing Lime, allow for
a larger production and ensure a better finished product. A small plate vibraior for this purpose is
presently being tested al Lhe Auroville Building Centre.
- Lastly, cure in a natural way by using solar energy with a system of curing dishes and curing
hoods. These are being used at CSR - Biogas Technology for the manufacLurc of ferrocement
biogas plants and water Lanks. Another improved way of curing is by using sLeam. Doors could be
cured and ready wilhin a few days employing this technique.
FerrocemenL doors can be used in a variety of applications:
- They can replace steel doors in induslrial settings and low-cost wooden doors for housing
projects because of their strength, durability and economy.
- They can replace asbestos panel doors in bathrooms, because they are waterproof and do not
pose health or environmental hazards.
- They can be used as balcony or back doors because of their durability, safety, waterproof and
non-warping qualities.
- They can be used as double doors for larger openings.
- They can be manufactured in different shapes and styles for differenL applications and can be
decorated with plaster of Paris ornaments for a superb finish.
CONCLUSIONS
A ferrocement door could become an alternative for a wooden door. What makes it attractive
is that it can fulfill the needs of urban as well as rural houses and other buildings.
The use of the above described technique is not restricted to doors alone; it can also be used IO
produce window shulters, small shelves, covers for water tanks, fixed louvers, and other similar
structures.
ACKNOWLEDGEMENTS
The extensive research and application work done in ferrocemem technology for CSR by Mr.
Uli Hauser from West Germany is hereby acknowledged and appreciated.
REFERENCE
l. Paul, B.K., and Pama, R.P. 1978. FerrocemenL Bangkok: International Fcrroccment In-
formation Center.
2. Robles-Austriaco, L. et al. editor. 1985. Proceedings of the Second International Sympo-
sium on Ferrocement. Bangkok: International Ferrocement Information Center.
3. Kaushik, S.K. and Gupta. V.K. 1988. Proceedings of the Third International Symposium
on Ferrocemenl. Roorkee: Civil Engineering Department, University of Roorkee.
4. Baetens, T., and Hauser, U. 1988. Ferrocement biogas application. In the Proceedings of
the Third International Symposium on Ferrocement, 175-180. Roorkee: Civil Engineering
Department, University of Roorkcc.
Journal of Ftrrocemtnt: Vol. 20, No. 4 , Oc1o~r 1990 367
As a part of on-going investigations for utilization ofbamboo grid inferrocement, the develop-
ment oflarge span bambooferrocement (BFC) elementsfor flooring and roofing was undertaken. The
study on BFC elements of size 1.6 mx13 m and of varying thickness (30 mm and 40 mm) indicates
that these elements meet the serviceability criteria laid down in the Bureau of Indian Standards.for
most of the cases of loading and support conditions.
A theoretical analysis by the orthotropic plate theory, using the.finite element approach, was
carried out to predict the structural behavior of BFC elements; and the computed load deflection
curves were compared with experimental ones, to a known degree of accuracy.
Based from the results of this investigation and considering BFC slab costing, the use of
ferrocement slabs is recommended/or flooring and roofing in low cost housing program.
LIST OF SYMBOLS
INTRODUCTION
Bamboo fcrrocement (BFC) is a composite obtained by replacing the skeletal steel grid in
ferrocement by bamboo grid. It was established [1] that BFC slabs upto an effective span of 1.5 m can
be constructed for use in residential public buildings. This paper reports the construction, testing and
theoretical analysis of large span BFC elements.
Constructjon
The bamboo ferrocement slab was 1.6 m x l .3 m in size and 1.6 min length. The length selected
allows for a bearing of 100 mm (50 mm on each end) and an effective span of 1.5 m. The effective
width of the slab was kept similarly to 1.2 m. This was reduced to make the slab less bulky and easy
to handle. The thickness of the BFC slab was kept Lo 30 mm lo attain a serviceability limit,
span/deflection ratio, of I 50 [l). The Bureau of Indian Standards [2] prescribes the span/deflection
ratios as 250 and 350 for buildings with or with out partitions respectively, along with a few other
conditions. The span/deflection ratio for ribbed ferrocemenL element was suggested as 200 by Kaushik
•Assistant Professor, Depanmcnt of Civil Engineering, Madan Mohan Malaviya Engioccring College, Gorakhpur-273010,
India.
368 JourNJ/ of Ft"ocUMnt: Vol. 20, No. 4, Octobtr 1990
et al. [3]. As such, with a view to improve the serviceability limit, it was also decided to test BFC
elements of 40 mm thickness in addition to the 30mm thick slabs. Increase in thickness was achieved
by using bamboo strips of 8 mm to 10 mm. The reinforcement cage is shown in Fig.I.
The size and designation of the two set of slabs so cast, are shown in Table 1, other constituent
details of the slabs are given in Table 2.
TESTING
Both set of slabs were tested for flexure by supporting them on two/four sides, under monotoni-
cally increasing uniformly distributed load (UDL). The size of slabs being large, UDL was applied
through sand filled gunny bags. The deflections were measured at the middle and quarter points. The
position of dial gauges is as shown in Fig.2
J011Tnal of Ferrocement: Vol. 20, No. 4, October 1990 369
( 400 )
1
j I
----:---4r---+---- ~
---4---~---l1----
I
I
I
I I
I
I
I
I
tl
IO
C\I
"'
EXPERIMENTAL RESULTS
The load-deflection curves for the two set of slabs in the elastic range, are shown in Figs. 3
and 4. The significant data obtained from the curves is shown in Table 3.
Floor of public s30 5.0 7.5 9.0 1500 166 All sides
building s.o 5.0 7.5 4.0 1500 375 supported
370 Journal of Pt rrocem.ent: Vol. 20 , No. 4, Octobtr 1990
12
5
10
4 .
8
N- 3
E
.
.....
z
0
--·- 1
1
I
! ..J
0
2
4 ::>
\ iS±!-4"..'JOf;b
~ s. o
-0---0- S 3 0
0 4 6 8
2
2 4 6 8 10
Central da flaclion ( b) (mm)
Centro! dellecrion (mm) ( b )
Fig. 3. Load-deflection curves for S, 0 and S, 0• Fig. 4. Load - Deflection Curve for S, 0 BFC Slab supported
on 1wo opposile sides.
DISCUSSION
It may be noted from Fig.3 and Table 3, that at a service load of 5 kN/m 2 the span/deflection ratio
for the S30 and S40 set of slabs are 166 and 375 respectively. As per the code [2] the service loads on
floors and roofs of residential buildings are 2 k:N/m1 and 1.5 kN/m2 respectively and the span deflection
ratio for these cases are 416 and 577 for S30 and 937 and 1364 for S40 slabs respectively.
Thus for the S40 slab, span/deflection ratios are within the prescribed serviceability limit of the
code [2] for all cases discussed, while the 530 slabs satisfy the serviceability criteria for loads on
residential buildings only i.e. service loads of 2 kN/m 2 and 1.5 kN/m 2•
In case, the slabs are supported on two shorter sides, only the S40 slab satisfies the serviceability
criteria for loads on residential buildings. The results for S» slab for this case fall outside the prescribed
limits.
The limit analysis of ferrocement thin slab and of ribbed ferrocement elements based on
orthotropic plate theory has been presented by Kaushik et al. [4,3). The BFC slab elements was
analysed by the orthotropic plate theory proposed by Mindlin (5). This theory has been used for
analysis of ferrocement plates by Ganga (6). The salient features of this theory are shown in
Figs. 5 and 6.
Formulation of equations for Mindlio's plate theory in which the transverse displacement of the
mid·plane [w] and the relations of lines initially normal to the mid·planc (8, OJ which are treated as
independent variables, is considered. The transverse shear deformations sllown in Fig.5 and theare
average rotations 'P,. and <p1 are expressed as
Jownal of Ferrocement: Vol. 20, No. 4, October 1990 371
y
My • My,y dy Qy + Oy,y dy
Fig. 5. Shear deformations. Fig. 6. Moments and shears per unit length.
<px =w ,%
- 8x and <p' = w..., - 8, (1.1)
and r. 1tJ
=-(u + v')=z(8 + 8)
" %o1 '
(1.3)
The equilibrium of the plate element is shown in Fig. 6, the vertical equilibrium is expressed
as
Q =M -M . (1.5)
' '" "'"'
Similarly, moment equilibrium about the y-axis is given by:
Q =M -M . (1.6)
% ""' "'"
372 Journal of Ferrocem£nt: Vol. 20, No. 4, October 1990
These three first order differential equations of equilibrium can be combined to give a second
order equation relating moments to load intensity. Eq. ( 1.5) is differentiated with respect toy, Eq. ( 1.6)
is differentiated with respect to x, and the results substituted into Eq. (1.4) to give:
The constitutive equations for a plate with orthotropic material properties with the (x,y ) axes
positioned parallel to the material property axes are
v = [Q
l
{Q Q ]
"· J
[D1] =[ D, D, 0
D 1 D1 0
0 0 Dxy
[Dsl =r~"s:]
{9
I
v = [-9 ""'
- 9 9
J.J ""
+ 9 ]
'"'
{<pI V = [w ,X
- 9.z wiJ - 9]
J
3
Ext
Dx=
12 (1-V;iyVy.J
3
E1 t
D,=
12 (1-v;iyv,.J
Journal of Ferrocement: Vol. 20, No. 4, October 1990 373
3
D:xy = G:xyt
2
DI =v ry Dx
The differential equations of plate bending are obtained by combining the equilibrium and
constitutive equations. Eqs. (3) are differentiated and substituted into Eq. (2.)
FINIIB ELEMENT
The finite element used in the above analysis is the' HEIBRORSIS' element. The details of which
have been presented by Hughes et al, [7]. The BFC slab is divided into the requisite number of finite
elements, depending upon the desired accuracy.
ANALYSIS
Using the above referred plate bending equation and the finite element, the analysis is performed
by the standard procedures of the finite elements method [8]. The entire analysis has been
programmed in FORTRAN 77. To generate the flexural and shear element stiffness matrices, the
modulii of elasticity E J: and EJ and the shear modulus G ry in the elastic range have been calculated by
the law of mixtures as follows:
G:xy
The other input data required in the program for analysis is the Poisson's ratio for wiremesh,
mortar and bamboo. These values have been taken as 0.25, 0.15 and 0.00 respectively. Since the
bamboos are located at near neutral axis, and more over they can swell as shrink, the estimate of their
Poission's ratio as zero is suitable.
With these inputs the analysis is performed for the given loading intensity and boundary
conditions.
374 Jo11Tna[ of Ferrocenuml: Vol. 20, No. 4, October 1990
The output from the program consists of displacements and rotations at nodal points of each
element. Thus, by a proper choice of the size/number of finite elements, the deflection at any desired
point, and consequently the deflected shape of the slab can be predicted to a known degree of accuracy.
Having thus determined the maximum deflection at the critical point in the slab. For a given span and
loading, the span/deflection ratio can be calculated. The output also gives the bending moment, the
twisting moment and the shear forces. Thus, moment curvature curves can also be plotted.
For the purpose of comparison, the UDL versus central deflection curves for the S40 series slab
were computed by the finite element model [9] for different boll(ldary conditions, viz., (a) all four sides
supported (Fig. 7) and (b) two opposite shorter sides supported (Fig. 8).
The comparison of theoretical and experimental results is presented in Fig.8 in the elastic range.
The maximum deviation of theoretical results from the experimental values was 13%. These
theoretical results have been obtained by subdividing the BFC slab into six finite elements. The
accuracy of theoretical prediction depends on how finely the slab is divided. If larger number of finite
elements are selected, the accuracy can be improved further.
4 f!'..!_~_*.9-¥ ~ f,
(--1600~ ~
;; 3
E
--o--<>--0- Theoretical
'z
~
--0--0---0- THEORETICAL
~ Experimental _J 2 --t:r--b--A- EXPERIMENTAL
0
::>
2 4 6 8
2 4 6 8
Central deflection (mm) ( /) )
Central deflection {mm) ( b)
Fig. 7. Central deflection (mm) (5) Fig. 8. Comparison of Result for S40 slab supponed on two
opposite sides.
CONCLUSION
Following conclusions can be drawn from the development work, presented in this paper,
regarding large span BFC elements.
(a) If the performance of the BFC slab is judged on the basis of the existing serviceability
criteria of the code (2) as applicable to reinforced cement concrete, the large span BFC slab (1.6 m x
1.3 m size) should have a thickness of 40 mm to meet the requirements of roofing and flooring elements
Journal of Ferrocement: Vol. 20, No. 4, October 1990 375
of residential buildings, as will as public buildings, carrying a service load upto 5 kN/m 2 •
(b) If however, the limits of serviceability i.e. span/deflection ratio are respecified as suggested
in earlier works [1,3], then the thickness of 30mm will also be suitable. In any case, for residential
buildings only, the 30 mm thick BFC slabs, meet even the existing serviceability limits. This slab
should, however, be used supported on all four sides.
(c) Since both the slabs are well within the elastic range, for all the above cases discussed, they
remain crack free in service.
The relative cost of bamboo ferrocement slab as compared to ferrocement slab can be calculated
on the basis of comparing volume fraction of bamboo skeletal grid with steel skeletal grid. Since
bamboo is cheaper than steel in most developing countries, the cost of bamboo ferrocement slab is
likely to be less than ferrocement slab. For this research activity, the cost of bamboo ferrocement slab
was 70% of the ferrocement slab.
It may be noteworthy to mention that a technology transfer project with the assistance of Council
of Science and Technology, Uttar Pradesh, India has been taken up. The project envisages the
construction of model of low cost houses utilizing BFC elements, and providing technical assistance
to the local population for the construction of such houses.
REFERENCES
1. Vijay Raj. 1989. Development of bamboo based ferrocement roofing element for low cost
housing. Journal ofFerrocement 19(4): 331-337.
2. Bureau of Indian Standards. 1983. National Building Code of India. New Delhi: Bureau of Indian
Standards.
3. Kaushik, S.K.; Trikha,D.N.; Kotdawala,R.P.; and Sharma, P.C. 1984.Prefabricated ferrocement
ribbed elements for low cost housing. Journal ofFerrocement 14(4): 347 -364.
4. Trikha, D.N.; Kaushik, S.K.; and Kotdawala, R.R. 1981. Limit analysis offerrocement thin slabs.
Journal ofFerrocement 11(2).111 -126.
5. Mindlin, R.D. 1951. The effect of transverse shear deformation on the bending of elastic plates.
Journal of Applied Mechanics 18: 31 -38.
6. Ganga, P.K.V. 1985. Finite Element Analysis ofFerrocement Plates, M. Tech. Thesis. Depart-
ment of Civil Engineering, Indian Institute of Technology, Kanpur, India.
7. Hughes, J .R., and Cohen, M. 1978. The Heterorsis finite element for plate bending. Computers
and Structures 9 : 445 -450.
8. Bathe, KJ. 1982. Finite Element Procedures in Engineering Analysis. New Jersey: Prentice Hall.
9. Vijay Raj. 1987. Development ofFerrocement Based Bamboo Reinforced Roofing Elements for
Rural Housing. Ph.D. Thesis, Avadh University, Faizabad (U.P.) India.
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 377
The main objective of this paper is to propose a simple construction technique offerrocement
water tanks sui.tablefor rainwater collection in developing countries. Based on an analysis ofthe water
tanks and the test results of the mechanical properties offerrocement elements, two cylindrical tanks
of5 rrr and 16 m1 were designed, constructed and tested. The test results and the salient features of
design and construction are presented.
INlRODUCTION
In the rural areas of many developing countries, there is a scarcity of water for drinking and
washing. Traditionally rainwater is collected for such usage therefore there is a need to provide simple
and economical storage facilities which can be constructed with unskilled labor. Although steel tanks
have been commonly used for this purpose, they have disadvantages such as high cost, rusting and
consequent maintenance and limited life-span due to corrosion. The use of reinforced concrete water
tanks poses a problem of different nature such as heavier and more massive construction with the
requirement of form work. In view of the above, the present study is devoted to the application of
ferrocement instead of conventional materials in the construction of cylindrical water tanks.
In recent years, a great deal of interest has been created within the Southeast Asian region on
the potential applications of ferrocement in the fields of agriculture, housing and industry. Extensive
investigations have been carried out on practically all aspects of the mechanical properties, construc-
tion techniques and various possible applications of ferrocement and the basic technical information
for the design and construction offerrocement is now fairly well-established [1-4 ]. Since ferrocement
has a high tensile strength to weight ratio, it is ideally suitable for the construction of thin-walled
structures such as water tanks. Ferrocement tanks of 20 m3 capacity have been in use in New Zealand
since the late 1960's [5].
In this study, two ferrocement cylindrical tanks of 5 m3 and 16 m3 capacities were analysed,
designed, constructed and tested. The salient features of design considerations, construction tech-
niques and test results are discussed.
DESIGN CONSIDERATIONS
The adopted water tank design consists of a cylindrical wall rigidly connected to a circular base
plate at the bottom and covered by a truncated conical roof on the top as shown in Fig. I.Two tanks
designated as tank A and tank B were analysed using linear elastic theory for thin shells. Each of these
tanks has a wall height of 1.8 m; the internal diameters arc 2.0 m and 3.6 m for tank A and tank B
respectively. Both tanks have a wall thickness of 35 mm whilst the base thicknesses are 35 mm and
50 mm for tank A and tank B respectively. In each case, the roof has a thickness of 25 mm and slope
of 1 : 3. An opening of 0.8 m diameter is provided at the center for service requirement.
The analysis was divided into two parts. The first part dealt with the analysis of the cylindrical
wall by imposing appropriate boundary conditions on the junction with the base plate. The second part
dealt with the analysis of truncated conical roof by considering the compatibility conditions governing
the displacement and rotation of the junction between the roof and cylindrical wall. The imposed loads
on the roof consist of a uniformly distributed load of 0. 75 kN/m 2 and a ring load at the top supporting
the ring of 0.6 kN/m. The detailed analysis and results are given in references [6] and [7].
The analysis shows that shear force acting on the bottom of the cylindrical wall due to hydrostatic
load is maxim um at the base of the tank, with magnitude of 1.21 kN/m and 1.72 kN/m for tanks A and
B respectively. The maximum bendingmomentoccursatadistanceof 120 mm and 180 mm from the
base with values of 48.7 Nm/m and 82.6 Nm/m respectively for tanks A and B. On the other hand,
the maximum hoop tension occurs at a location distance of 280 mm and 360 mm from the base with
magnitudes of 13.6 kN/m and 22.6 kN/m respectively for these tanks. The bending moments at the
base of the wall are 11.7 Nm/m and 40.4 Nm/m for tank A and tank B respectively. The bending
moment in the meridional direction and the hoop tension at the top of the wall are 53.5 Nm/m and
5.2 kN/m respectively for tank A and 114.6 Nm/m and 14_.2 kN/m respectively for tank B.
For a ferrocement water tank to fulfill its intended function, not only must it be watertight, its
structural components must also be proportioned to provide adequate resistance against cracking
under service loads. ACI Committee recommends a minimum volume fraction of reinforcement of
1.8% for water retaining structures. On the other hand, from the results of the analysis, it can be
concluded that the bending moment and hoop tension are the two main factors which determine the
thicknesses and reinforcement for the base, wall and the roof. Thus, for an element subjected to bending
moment M and axial force N, the required thickness may be obtained by satisfying the following
criterion:
(1)
where Ne and Mc are respectively the tensile force and the bending moment required to cause cracking
in the element. They can be obtained from tensile and flexural tests respectively. A safety factor of
three has been included in the design criterion.
In view of ACI Committee's recommendation and the design criterion according to Eq. (1), the
reinforcement details for tank A and tank B including the details of connections and roof opening were
selected as shown in Fig.I. It is noted, however, that the roof section has a volume fraction of
reinforcement of 1.4%. This is considered satisfactory as the roof section is not subjected to the
requirements of water-tightness. The properties of the constituent materials are shown in Table 1. The
mortar mix with a cement-sand-water ratio of 1: 1.5:0.4 was selected in view of its porosity, desired
compressive strength and workability [3].
Type 1 ordinary portland cement should be used. Sand used should be clean, hard, strong and
free of organic and deleterious substances.
Journal of Ferrocem£nt: Vol. 20, No. 4. October 1990 379
800
35
1 ..
2000 (Tonk A l ...,
3600 (Tonk B)
(All dimension in mm)
M
___; f_29mm
6mm diameter r-, El-
ring reinforcement :; : ~ i
1, 1"'-f
.,.....::;_!/..,,./. -- --
J~ ~~>;
-C_ 25mm
50mm (Tonk B) Legend
1
11 11 35 mm (Tonk A) - - -Welded finemesh,
11111 j .
11 111 ___ ___ 12.5x12.5 mm spocmgJ
11
~
''L.:__________ wire size 122
. mm111
T - -- BRC weldmesh ,
E 150x 150 mm spacing,
wire size 5.4 mm r6
Plain Mortar
Cement : sand : water 1 : 1.5 : 0.4
Crushing strength 35 N/mm 2 -40 N/mm 2
Mododulus of elasticity 2.8 x 104N/mm 2
CONSTRUCTION TECHNIQUE
The site chosen for water tank should have adequate bearing capacity to ensure uniform support
of the base and should not be uncompacted backfill. The ground should be levelled to the desired slope
of 1 : 40 to 1 : 100 to provide for natural drainage of the tank through the scour pipe for cleaning
purposes. A layer of lean concrete, 30 mm to 50 mm thick should be placed on the soil to provide a
clean bed for laying of reinforcement. The sequence of preparation of reinforcement for the base, wall
and roof are discussed with sketches in reference [6]. The reinforcement for the base is placed on the
top lean concrete floor with spacers to ensure proper cover (Fig.2). With the outer layer of wire mesh
of the base untied, the base is plastered to the required thickness. Before plastering, the scour pipe
should be in place and sealed with plumbing sealant to prevent clogging. The entire base should be
plastered, making sure that mortar penetrates into the bottom layers of meshes. After proper curing
for 3 days, the reinforcement for the wall and the roof may be assembled on the the base. Figs. 3 to
10 show the placing of reinforcement and plastering of the tank A and tank B. It should be ensured
that auxilliary fittings such as overflow pipe, outlet pipe and scour pipe should be placed at the proper
positions before plastering. Additional layers of wire meshes may be added around the fittings.
The plastering should be carried out in tiers starting from the base and advancing upwards. After
each tier was completely plastered from the outside the remaining parts were plastered from the inside
ensuring that proper compaction and proper cover of about 5 mm for the reinforcement is provided on
finishing both the inside and outside. Excessive movement of the reinforcement cage should be
avoided during plastering. For the smaller tanks the plastering of the wall and roof may be carried out
in one operation. In the case of larger tanks the roof may be plastered 3 days after the wall has been
properly cured. Some propping of the roof may be necessary for the larger tanks. The tank should be
Journal of Ftmx:t!Mlll: Vol. 20, No. 4, Oc1obtr 1990 381
Fig.2. Assembled reinforcement for the base Fig.3. Wall reinforcement in place after the base has been
cast and aired
Fig.4. Bending outer layer of BRC mesh in the wall on 10 the Fig.5. Wall and roof reinforcement of tank A.
conical roof
cured properly for about 28 days. Moist jute or burlap bags soaked in water should be used for curing.
Painting if required should only be carried out after the tank has completely dried out.
TEST RESULTS
After curing for 28 days, the water tanks were filled to the height of 1.6 m and no leakage was
observed for both tanks. The tanks were kept filled for almost two years and the performance was
monitored carefully. It was noticed that there was no leakage or reduction in height of water. It is of
interest to mention that no waterproofing compound was used in this project.
The tanks were instrumented with electrical strain gauges on the exterior surfaces of wall and
transducers were used to measure horizontal deflection. The hoop stresses determwed from strain
readings agree closely with theoretical results as shown in Fig. I I for the tank A and tank B. The
deflections at fuJI capacity were also very small (less than 0.3 mm).
Journal of Ferrocem£nl: Vol. 20, No. 4, October 1990 383
1.5 - Theoretical
- - - Experimental
E
(Tonk A) (Tonk B)
E
~
m ' ' :..
" 0.5
~
Ci
0 0.5 0 0.5 10
2
Circumferencial stress ( N/mm )
CONCLUSION
The foregoing feasibility study shows that ferrocement can be used as a construction material for
water tanks with simple construction techniques suitable for rural applications. The successful
performance of the prototype tanks of 5 m 3 and 16 m3 capacities confirms the viability of using
ferrocement water tanks of the proposed design which can be developed as a community project in
rural areas of many developing countries.
ACKNOWLEDGEMENT
This study was carried out with funds provided by the International Development Research
Centre (IDRC), Regional Office for Southeast and East Asia. The support is gratefully acknowledged.
REFERENCES
7. Lee, S.L.; Paramasivam, P.; Ong, K.C.G.; and Tan, K.H. 1987. Ferrocement cylindrical
tanks for rainwater collection in rural areas. In the Proceedings of Third International
Conference on Rainwater Cistern Systems Cl2-20. Khon Kaen: Khon Kaen University.
Journal of Femx:eml!nl: Vol. 20, No. 4, October 1990 385
INlRODUCTION
CONSTITUENT MATERIALS
1 Keynote Address presented at the First National Seminar on Ferrocement, Malaysia on 16-17 January 1990. Publish with
permission from the author.
*Professor, Division of Structural Engineering and Construction, and Technical Advisor, International Ferrocement Infor-
mation Center, Asian Institute of Technology, Bangkok, Thailand.
386 Journal of Ferrocement: Vol. 20, No. 4, October 1990
Wire Mesh
The effect of the orientation of wire mesh on the behavior of ferrocement in tension and in
flexure are investigated by several researchers. For hexagonal wire mesh, the behavior in tension
and flexure were studied by Walraven and Spierenburg [2] and Al- Rifaie and Trikha [3]; studies
on flexure alone are also made by Naaman and McCarthy [4]. Parameters that they studied include
the orientation, number of layers of mesh and others.
Walraven and Spierenburg [2] found that ferrocement reinforced with hexagonal wire
mesh can be dealt with in the same way as one reinforced with orthogonal mesh. The effective
reinforcement ratio to be used in calculations for the longitudinal direction is dependent on the
number of layers over the cross section, the cross sectional area of a single wire, the thickness of
the member and the length of the side of the hexagon. In the transverse direction, the reinforcement
ratio to be used is 60% of the value for the longitudinal direction.
Naaman and McCarthy [4] found that the efficiency of hexagonal meshes placed parallel to
the loading direction is almost as good as that of square meshes, provided differences on yield
strength of reinforcement are accounted for. A reduction of 30% to 40% in efficiency is expected
when the mesh is placed transverse to the loading direction. Al-Rifaie and Trikha [3] found that
strength of ferrocement with the mesh in the transverse direction is markedly different in flexural
tension and direct tension. They have proposed expressions to estimate the Young's modulus,
flexural tensile strength and direct tensile strength in the transverse direction.
Al-Rifaie and Trikha [5] investigated the effect of arrangement and orientation of
hexagonal wire mesh on the behavior of ferrocement. Simply supported slabs under uniform
loading, with varying number of mesh layers, slab thickness and arrangement were tested under
three different arrangements of mesh reinforcement : (1) all layers oriented in one direction; (2)
alternate layers equally spaced and oriented in orthogonal directions; and (3) twin layers, each
twin layer consisting of two orthogonally oriented meshes in contact with each other. It was
found that the arrangement consisting of twin layers with two meshes orthogonally oriented and
placed in contact is superior to the other two arrangements in terms of load-deflection behavior,
first cracking load, ultimate load and crack patterns at failure. For slabs under biaxial state of
bending, arranging the meshes in twin mesh layers will result in isotropic behavior of the slab and
higher first cracking and ultimate loads.
Paramasivam and Sri Ravindrarajah [6] also investigated the effect of arrangement of rein-
force'llent along the cross section on the behavior of ferrocement in tension and flexure. They
studied the feasibility of using bundled mesh layers placed near the top and bottom surfaces or at
midsection of the ferrocement element. The variables considered are the number of mesh
layers, the thickness of specimens, and the reinforcement arrangement. It was found that under
tension, the strength of ferrocement at first crack and at ultimate is not affected significantly by
the arrangement of the reinforcement. Under simple bending, the first crack strength of ferroce-
ment having bundled reinforcement placed near the top and bottom surfaces is superior than that
having evenly distributed reinforcement arrangement; however, that of ferrocement having
bundled reinforcement placed at the center is similar to that of plain mortar only. Ferrocement
having bundled reinforcement placed near the surfaces also showed reduced crack width and
increased intensity of cracking at failure compared to other arrangements of reinforcement
Kaushik et al. [7] investigated the efficiency of mesh overlaps in ferrocement elements
under flexure. Test specimens with varying length of overlap in square woven meshes and with
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 387
different wire diameters and mesh openings were tested in flexure. It was found that the mortar
strength, diameter of the wire and mesh opening influence the overlap length; higher mortar
strength, smaller wire diameter and smaller mesh opening require shorter overlap length. Kaushik
et al. [7] recommended that even if the stress in the fiber is small, it is desirable that a minimum
overlap of 100 mm be provided. To cover shortcomings in quality control at sites, it is
recommended that this value be increased by 25%.
Nanni and Hashim [8] investigated the effect of expanded metal mesh splicing for ferroce-
ment specimens under flexure. The variables tested are beam depth, length of mesh overlapping,
number of reinforcement layers, position of the splice with respect to the continuous reinforcement
layers, type of mesh, and compressive strength of the mortar matrix. As a result of the
investigation, it was recommended to use at least 152 mm total mesh overlapping at joints that
occur in a tensile zone. For 3-layer or more construction, the spliced layer should be
sandwiched between the continuous layers. For 2-layer construction, the spliced mesh should be
positioned closer to the neutral axis than the continuous mesh.
Ballarin and de Hanai [9] investigated the behavior of ferrocement reinforced with welded
wire meshes of larger openings than those usually employed in ferrocement by conducting tension
and flexure tests on test specimens. Specimen deflections, mortar and steel strains and crack
spacing and width were measured at every loading stage up to failure. From the results obtained,
it was found that general ferrocement formulation is not suitable for ferrocement reinforced with
larger openings welded wire meshes.
Wang [10] investigated the mechanical properties of ferrocement reinforced with
prestressed skeletal bars. He proposed a method of calculating the strength of prestressed
ferrocement members and conducted tests on specimens reinforced with pretensioned skeletal
bars and woven square meshes. It was found with prestressed skeletal bars, that better mechanical
behavior of ferrocement such as higher crack load capacity, larger modulus of deformation and
favorable cracking behavior, can be achieved. The proposed method of calculating the strength of
members is in good agreement with experimental results.
Substitute Materials
The substitute materials investigated were bamboo mesh, bamboo skeletal reinforcement, rice
husk ash cement and lime admixture. Chembi and Nimityongskul [11] investigated the use of
bamboo mesh to replace steel wire mesh in ferrocement water tank. A bamboo cement tank of 6
m3 capacity was constructed in 1983. The tank was kept alternatively full and empty of water to
simulate actual field condition and was monitored regularly. After 5 years, they found that the
tank has not shown structural defects. Bamboo reinforcement 0.3 m from the top of the tank
was investigated and found in good condition.
Venkateshwarlu and Raj [12] investigated the use of bamboo to replace skeletal steel in
ferrocement roofing elements. Slabs reinforced with bamboo strips as skeletal reinforcement and
chicken wire mesh were subjected to monotonically increasing uniformly distributed load to
study the load-deflection behavior and to determine its serviceability limit (span/deflection).
The investigation showed that by using bamboo, the cost of roofing elements comes to about
50% of reinforced concrete and 70% of ferrocement elements. The slabs can be prefabricated
in the factory or can be produced at the site manually. The serviceability limit was suggested
as 150 and it was observed, that at deflections up to 10 mm, no cracking occurred. Hence, roofing
388 Journal of Ferrocemenl: Vol. 20, No. 4, October 1990
elements can be produced up to a maximum span of 1.5 m and can be used in multiples to cover
longer spans.
The Ayuthaya Boat Building College in Thailand has developed bamboo-cement boat [13].
Bamboo splints was used as skeletal reinforcement with hexagonal wire mesh in constructing
ferrocement boats.
Choeypunt et al. [ 14] investigated the use of rice husk ash (RHA) cement for ferrocement. The
RHA cement employed constitute 50% RHA and 50% Portland cement. The properties investi-
gated are compressive strength, tensile strength, flexural strength, impact strength, heat of
hydration of cement and acidic resistance. The test results showed that RHA cement mortar has
better resistance to acidic attack than Portland cement mortar. RHA in ferrocement improved its
impact strength; however, its compressive, tensile and flexural strength decreased.
Raj [15] investigated the use of lime as an admixture in ferrocement The amount of lime
added was 15% by weight of the cement, applied as fine powder. It was found that during the fresh
state, adding lime in the ferrocement mortar causes the mortar to become more plastic, records
higher slump and increases its workability. The optimum lime dose was found to be between
15%-20% by weight of cement and the lime dose should be added either in the form of fine powder
or putty.
MECHANICAL PROPERTIES
Tension
On the cracking of ferrocement in tension, Grabowski et al. [ 16] and Seed et al. [ 17] made
studies on the measurement and observation of cracks of ferrocement subjected to tension using
different methods.
Grabowski et al. [16] evaluated the possibilities of using moire method to detect and localize
microcracks and determine their width in ferrocement elements subjected to tension. It was found
that the moire method is very suitable for the observation of the crack development in
ferrocement, both for short and long term tests. Seed et al. [ 17] also investigated the use of
linear potentiometers as an accurate means of measuring the first crack strength of ferrocement in
tension. Several tests were perlormed on ferrocement elements with different quantities and types
of wire mesh reinforcement. It was found that linear potentiometers can be used successfully to
detect and, in some cases, measure cracks in ferrocement elements before they were observed
visually.
Several investigations were conducted on the determination of the first tensile crack strength
of ferrocement. Recent studies include Chowdhury [18] and Al-Noury and Huq [19]. Al-Noury
and Huq [19] also studied the modulus of elasticity of ferrocement in tension. According to
Chowdhury [18] the first tensile crack strength of ferrocement can be rationally predicted on the
basis of the linear elastic fracture mechanics (LEFM). The numerical method suggested can lead to
a better design against cracking for certain applications of ferrocement.
Al-Noury and Huq [19] investigated the behavior of ferrocement in tension. They have
proposed expressions for predicting the first crack strength and modulus of elasticity offerrocement
in the uncracked and cracked range. It was found that the first crack strength of ferrocement in
tension may be predicted on the basis of the strain at the limit of proportionality of mortar and the
Journal of Ferrocement: Vol. 20, No. 4, October 1990 389
uncracked modulus of fcrrocement. The modulus of elasticity of ferrocement in the cracked range
can be predicted on the basis of the behavior of an equivalent composite model with aligned
wires. Beyond first crack, the crack formation mechanism in ferrocement in the cracked range is
related to the matrix-wire interfacial bond.
Investigations on the crack width and crack spacing of ferrocement in tension were
studied by Nedwell and Vickridge [20], Chen and Zhao [21] and Akhtaruzzaman and Pama
[22]. Nedwell and Vickridge [20] investigated the onset of cracking in ferrocement with different
types and quantities of wire mesh subjected to tension. The identification and measurement of
crack positions and sizes was performed by the use of linear potentiometer. Chen and Zhao
[21] performed a study on the calculation of crack width of ferrocement in tension. They studied
the development of cracks in fcrrocement elements with medium or low degree of reinforcement.
Based on experimental results and with triangular tensile stress distribution, a formula was
proposed to evaluate the crack width of fcrrocement elements under standard service loads and in
each stage of crack growth.
Akhtaruzzaman and Pama [22] performed an analytical and experimental investigation on
the crack spacing and crack width of fcrrocement in direct tension. The theoretical investigation
showed that the slip modulus, ultimate bond strength and modulus of elasticity of mortar have
negligible influence on crack spacing while the ultimate tensile strength of the mortar and the
volume fraction and modulus of elasticity of steel have significant influence on crack spacing.
The crack width is greatly influenced by volume fraction, modulus of elasticity of steel and
ultimate bond strength but very small effects from slip modulus, modulus of elasticity of mortar and
tensile strength of mortar. Results of the experimental work was in good agreement with the
theoretical result.
Other investigations undertaken include study on the short and long term behavior of
ferrocement in tension [23] and probabilistic analysis of tensile strength of ferrocement [24].
Desayi and Reddy [25] also studied strength and behavior of lightweight ferrocement in tension.
Compression
Kameswara Rao and Kamasundra Rao [26] investigated the stress-strain curve and
Poisson's ratio of ferrocement in axial compression. It was found that the specific surface is the
only factor which controls the behavior of ferrocement in axial compression. Equations
developed for predicting the increase in strength, strain and modulus of elasticity by regression
analysis were used to generate the stress-strain curve of ferrocement under axial compression.
They have found that ferrocement behaves linearly up to 50%-60% of the ultimate strength in
compression, beyond this limit the behavior becomes non-linear. The value of ultimate strength,
strain at ultimate strength and Young's modulus increase with specific surface area. All parameters
affecting the behavior of fcrrocement under compression can be combined to form a single non-
dimensional factor called the specific surface factor. The Poisson's ratio is found to be constant at
a value of 0.25 up to a stress level of about 60% of the ultimate strength and thereafter increases
fairly linearly with the stress level.
Flexure
Recent studies on the design of ferrocement elements in flexure include limit state of
390 JourNJ/ of Ferrocem£nl: Vol. 20, No. 4, October 1990
serviceability [27], computerized design and design aids [28], plastic analysis [29], and rigid-
plastic analysis [30]. Karunakar Rao and Jagannadha Rao [31] and Desayi and Balaji Rao [32]
proposed methods for the computation of ultimate moments of ferrocement in flexure.
Kuczynski [27] investigated the limit state of serviceability of ferrocement flexural members.
This limit state of serviceability in flexure is denominated by two phenomena: displacement and
cracking. Equations to determine deflections in short-term and long-term loading were derived
considering rheological influence. Allowable crack widths of ferrocement structures under different
service loads and methods to determine elongation in the tension zones for such loadings are given.
Mansur and Paramasivam [29] proposed a method to predict the ultimate strength of ferroce-
ment in flexure based on the concept of plastic analysis where ferrocement is considered as a
homogeneous perfectly elastic-plastic material. Simple equations are derived for direct design
of a cross-section. An experimental investigation was also conducted to study the behavior and
strength of ferrocement in flexure. It was found that the ultimate moment increase with increasing
matrix grade (decreasing water cement ratio) and increasing volume fraction of reinforcement.
This method can give satisfactory predictions of the ultimate moment capacity of ferrocement.
Naaman and Homrich [28] have proposed flexural design of ferrocement, based on the
concept of reinforced concrete analysis using the principle of equilibrium and strain compatibility,
by computerized evaluation and design aids. They have proposed a general methodology for the
analysis and design of ferrocement flexural elements.
Mansur [30] further investigated the validity of the rigid- plastic model to predict the
ultimate flexural strength of ferrocement. Test results indicated that within the practical range of
member thickness, either welded or woven wire mesh reinforcement furnish sufficient ductility to
justify a rigid-plastic analysis at collapse. Based on experimental observation of the behavior at
ultimate load and a comparison with the available test data, the rigid-plastic concept has been
justified for ultimate strength analysis of ferrocement. Using this method, design charts have
been developed for typical ferrocement sections similar to the one developed by Naaman and
Homrich [28].
Karunakar Rao and Jagannadha Rao [31] proposed a theory to determine the ultimate moment
of ferrocement elements based on the experimental evidence of the crack pattern, extent and
propagation of cracks, which gave an insight into the mechanics of development of moment of
resistance. Desayi and Balaji Rao [32] proposed two methods to predict the ultimate moments of
ferrocement elements. A bilinear method was used to predict the deflections of these elements
at different stages. The computed ultimate moments and deflections at working load level are
found to compare satisfactorily with experimental values of test specimens. Both methods are
found to give satisfactory agreement with test data and can be used in the design of ferrocement
elements in flexure.
Recent studies on cracking of ferrocement elements in flexure include those of Mansur and
Paramasivam [29] and Desayi and Balaji Rao [32]. Mansur and Paramasivam [29] found that the
first crack increase with increasing matrix grade (decreasing water cement ratio) and increasing
volume fraction of reinforcement. Lower matrix grade is more favorable with respect to cracking,
i.e. large number of cracks appear with smaller maximum and average crack widths. Higher
volume fraction of reinforcement provides more effective control of crack width. Desayi and Balaji
Rao [32] proposed a bilinear method to predict the first crack and deflections of ferrocement
elements at different stages. The computed cracking and deflections at working load level are
found to compare satisfactorily with experimental values of test specimens.
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 391
Shear
Mansur and Ong [33] investigated the behavior and strength of ferrocement in transverse
shear by conducting flexural tests on simply supported beams under two symmetrical point loads.
Thebeams were reinforced only with welded wire mesh, with the various layers of the mesh
lumped together at the top and bottom. Test results indicate that the diagonal cracking strength of
ferrocement increases as the span-to-depth ratio is decreased and volume fraction of
reinforcement, strength of mortar, and the amount of reinforcement near the compression face are
increased. Ferrocement beams are found to be susceptible to shear failure at small span-to-depth
ratios when volume fraction of reinforcement and strength of mortar are relatively high. In
general, however, shear failure is preceded by the attainment of flexural capacity.
Venkata Krishna and Basa Gouda [34] performed testing on ferrocement beams with
different volume fraction of reinforcement in transverse shear. It was found that the shear strength
depend upon strength of mortar, strength of wire mesh, volume fraction and shear span. Theoretical
expressions were developed for predicting the shear strength at first crack and collapse of ferroce-
ment beams with different type of wire meshes namely hexagonal, woven and welded. The
correlation between the experimental and predicted values was quite satisfactory.
Research on the behavior of ferrocement under combined bending and axial loads were
undertaken by Mansur and Paramasivam [35]. A further research by Mansur [36] is on the design of
ferrocement under combined bending and axial loads. Mansur and Paramasivam [35] found that
the conventional reinforced concrete analysis, with little modification, provides satisfactory predic-
tions of the bending-axial load interaction behavior. Test results indicate two distinct modes of
failure - primary compression and primary tension. The former type of failure occurs under
predominant axial loads, while the latter is caused by a moderate compressive load or tension. For
a particular eccentricity of the axial load, the number of cracks and the capacity of the section
increase with increasing volume fraction of reinforcement. Mansur [36] proposed a simple method
to predict the ultimate strength of ferrocement in combined loading applying the familiar rigid-
plastic concept. The rigid-plastic approach is found to be simple, provides good predictions of
the interaction relationship and suitable for the construction of design charts. It is satisfactory for
predicting the strength of ferrocement under combined bending and axial loads. To facilitate
design, non-dimensional charts can be developed for typical ferrocement sections.
Fracture Properties
In recent years, many attempts have been made to determine the fracture parameters which
characterize the fracture behavior of cementitious materials. Kaplan [37] was the first to apply
linear elastic fracture mechanics (LEFM) to determine the fracture toughness of mortar and
concrete. Later attempts have been made to apply elastic-plastic fracture mechanics (EPFM)
concepts to characterize the fracture behavior of concrete and other cementitious materials.
Three extensions of LEFM into the elastic-plastic region have been applied to concrete and
fiber reinforced concrete, namely J-integral, critical crack opening displacement (COD) and
R-curve analysis.
392 Journal ofFerrocement: Vol. 20, No. 4, October 1990
Recently, Desayi and Ganesan [38, 39], Gonzales [40] and Sanguansing [41] carried out tests
on notched and double cantilever beams to study the fracture behavior of ferrocement using the
concept of EPFM. They studied the fracture behavior of ferrocement using I-integral and CODc
approaches. They studied the effect of different parameters such as: percentage of mesh reinforce-
ment and initial crack length [38, 39]; notch depth specimen size and percentage of mesh reinforce-
ment [40]; and specimen span length and wire mesh opening [41]. They found that the I-integral
and the crack opening displacement (COD) are suitable fracture criteria for ferrocement. CODc and
R-curves, however, are not suitable fracture criteria.
Fatigue Resistance
The fatigue strength of the wire, as tested in air, is the primary factor affecting fatigue of the
composite. Singh et al. [42] investigated the influence of the reinforcement on the fatigue
behavior of ferrocement. They conducted fatigue tests on ferrocement slabs with different types
of mesh reinforcement, studying the effect of the size of wire, galvanizing of the wire and placing
of wire mesh in layers to the fatigue strength of ferrocement. Samples of the wires were also
fatigue-tested in air and a relationship is developed between the fatigue strength of each type in
air and in the composite. It was found that the fatigue of the wire in air and in ferrocement are
related. Most fatigue failures occurred by fracture of the wires and the range of repeated stress in
the wires gave the greatest influence on the fatigue strength of ferrocement. Ramli [43] also
investigated the fatigue properties of ferrocement composite in a marine environment. The effect
of corrosion fatigue on ferrocement composite was considered with particular attention to fatigue
life cycles of the specimen and to cracking and deflection behavior.
Impact Resistance
Reports attesting the favorable characteristics of ferrocement in collisions involving boats with
each other or with rocks are numerous. The main attributes include resistance to disintegration,
localization of damage, and ease of repair. However, due to experimental complexity associated
with measurement of impact resistance, little quantitative or comparative data exist. Drop-impact
tests on panels indicate that the severity of cracking inflicted varies significantly with the type
of reinforcement, but the fundamental governing parameter are not yet established. Test using
ballistic pendulums to produce the impact, and flow of water through the specimen after testing to
assess the damage show that damage decreases as the strength and specific surface of the mesh
reinforcement increase. However, at present the available information is insufficient to indicate
what constitutes an optimal reinforcing system from the point of view of impact resistance. The
factors which influence first-crack strength such as the type, geometry, and specific surface of
the reinforcement are probably of primary importance.
Snyder [44] introduced a rational definition of impact resistance. He defined the critical
impact resistance as the single strike impact energy required to produce the critical damage
condition in the panel. The critical damage condition of any ferrocement boat hull is considered
to exist when the flow of water under two feet head leaks through the damaged area at the rate of six
gallons per hour. In the last five years Grabowski [45], Achyutha et al. [46] and Raisinghani et al.
[47] made studies on ferrocement under impact. Grabowski [45] performed numerous tests on
ferrocement subjected to impact loads by conducting drop impact test and Charpy impact test.
Achyutha et al. [46] studied the impact resistance of ferrocement slabs by assessing local
Joiunal of Ferrocement: Vol. 20, No. 4, October 1990 393
Fire Resistance
A problem unique to ferrocement is potentially poor fire resistance because of the inherent
thinness of its structural form and the abnormally low cover given to the reinforcement. At
present, there is still limited information available on fire tests having been performed on ferroce-
ment.
Basunbul et al. [48] studied the fire resistance of ferrocement load bearing sandwich panels.
The fire resistance of the ferrocement wall was found to be encouraging for designers of ferroce-
ment buildings. Though the thin shell nature of ferrocement has raised questions about its fire
resistance, it was found that ferrocement retains much of the load bearing qualities of ordinary
reinforced concrete. Its heat transmission qualities are not as good as those of reinforced concrete
which would be just under four hours, but this latter consideration is more dependent on the mass of
the wall. Limited problems of spalling of the front face sheets occurred during the early portion of
the test but this spalling was not severe enough to cause serious structural damage during the
period in which the wall satisfied the ASTM E-119 performance criteria.
Creep
Swamy and Spanos [49] studied the creep behavior of ferrocement sections. Tests were
conducted on ferrocement slabs loaded at third points. The type and amount of mesh reinforce-
ment was varied, and both a cement and cement-fly ash matrix were used. Both creep recovery
and the residual flexural strength were determined. It was found that deflection could be a major
design criterion, and that it is the instantaneous rather than the time- dependent deflection that
dominates the behavior of ferrocement. The mesh reinforcement controlled both cracking and
slippage at cracks under sustained loading; cracking under sustained loading was not critical. The
total deformation recovery of ferrocement was about 65% of the total deformation.
Durability
Although the measures required to insure durability in reinforced concrete also apply to
ferrocement, three other factors which affect durability are unique to ferrocement. First, the
cover is small and consequently it is relatively easy for corrosive liquids to reach the reinforcement.
Second, the surface area of the reinforcement is unusually high, so the area of contact over which
corrosion reactions can take place, and the resulting rate of corrosion, are potentially high. Third,
although many forms of reinforcement used in ferrocement are galvanized to prevent corrosion,
the zinc coating can have certain adverse effects from gas bubble generation. All three factors have
varying importance depending on the nature of the exposure condition. However, in spite of these
unique effects, there is no report of serious corrosion of ferrocement not associated with poor
plastering or poor matrix compaction. To insure adequate durability in most applications, a fully
compacted matrix is necessary. A protective coating may be also be desirable.
The causes of degradation of ferrocement which include the corrosion of the reinforcement
by aggressive external agents and the corrosion of the mortar or microconcrete by aggressions of
external and internal origin were studied by Paillere [50]. The prevention of any degradation
requires, during the design phase, the application of essential principles, viz., optimum compact-
ness, suitable cement proportion, galvanization of reinforcements, and suitable thickness of the
reinforcement covering.
Alexander [51] presented the factors affecting the durability of reinforced concrete, then
based on these, discussed the factors influencing the durability of ferrocement. This is due to
similar behaviors of reinforced concrete and ferrocement with regards to durability where they
differ only in the degree of protection provided by their assembly. The superior resistance of
ferrocement to invading acid ions and gaseous co2 is due to the use of galvanized steel, fine
grained well-graded sands, low water cement ratios, chemical neutralization by the alkalinity of
rich mortars, and to compaction which is readily obtained as a consequence of the reduced
mass of the ferrocement.
Hope and Ip [52] suggested that the pH is not affected by the chloride ion concentration.
However despite this experimental evidence, it is unlikely depassivation of the steel would occur
without a drop in pH. The strongly cathodic protection afforded by galvanized surfaces cauticizes
the wire environment precipitating chlorides as chloro-aluminate salts. These precipitates provide
some blocking of pores.
RILEM Committee 48-FC has undertaken a worldwide survey on durability and mainte-
nance of ferrocement structures [53]. The technical and general information obtained indicates
that ferrocemcnt is a construction material widely used all over the world for many applications.
The survey also confirm that durability of ferrocement seems to be very good particularly where
the fcrrocement elements have been correctly used according to the designers requirements.
Sri Ravindrarajah and Paramasivam [54] investigated the influence of weathering on ferroce-
ment. They reported the results of an investigation into the effects of drying and wetting cycles
using both fresh water and sea water, and of curing in 6% NaCl solution on the strength and
stiffness of ferrocement in direct tension and flexure. The results indicated that the ultimate
strength and stiffness of ferrocement were not affected within the duration of durability tests, i.e.
by 1000 cycles of drying and wetting and by 9 weeks of exposure in 6% NaCl solution.
Baseer et al. [55] described methods to evaluate strength, water permeability and abrasion of
the surface layer of the ferrocement, on site. It was found that due to a wide scatter in strength,
permeability and abrasion for the in situ specimens, testing control samples in the laboratory alone
is not sufficient to estimate the in situ properties. Strength test alone is inadequate to define the
surface durability.
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 395
Corrosion
Corrosion is the deterioration of metals or alloy due to interaction with its surroundings. The
most common example of corrosion is the rusting of steel. Corrosion is normally a fairly slow but
complex process; however, due to presence of certain conditions, it may occur very rapidly. Many
of these can occur in ferrocement and avoiding them is one of the biggest problem. All
ferrocement marine structures, by virtue of their marine environment are liable to corrosion
attack. The danger of corrosion is enhanced in ferrocement by the extreme thinness of the cover
of mortar over the steel reinforcement. The corrosion process is often difficult to recognize
until extensive deterioration has occurred. The severity of the attack on structure will depend
basically on how well it has been designed and built, the materials used and what happens to it
when in and out of use.
Bowen [56] found that a hull built of any material will corrode or otherwise deteriorate if it
is improperly constructed or if is not properly maintained. Ferrocement is no exception.
Experiences from repairing ferrocement boats in Hawaii [57] clearly illustrated the problem of
corrosion due to permanent pipe frames in ferrocement boats. When a pipe frame corrodes inside, it
often manifests itself through a crack on the inside of the hull. If these cracks do not weep rust, the
cracks may not be a corrosion related problem but due to concentration of stress which will cause the
plaster to crack.
S. Carlos Group [58] found that all those that experience critical corrosion problems also
exhibit construction faults, deeply carbonated mortar, and excessive contents of calcium chloride.
However, other constructions where calcium chloride was also used do not present problems.
According to Ioms [59], after 20 years of using ferrocement produced by shotcrete laminating
methods, it was found that a 3 mm cover will protect the mesh against corrosion and that several
layers of mesh will in tum protect anything inside it.
According to Chalisgaonkar [60] some factors which control the rate of corrosion under one
set of conditions play a very minor part under other conditions. Such variations in the factors
controlling corrosion account for the complexity of the corrosion problem. These factors are mix
design, cover, carbonation, chlorides, electrolysis, coating and others. Rengaswamy et al. [61]
investigated various surface coatings to concrete and steel based on inhibited cement slurry for a
cantilevered loaded type model slab and found three suitable schemes.
loms [62] used a mixture of galvanized and ungalvanized mesh in the construction of a
towboat. He observed that galvanized lath had been passivated by exposure to the weather or no
visible bubble formation was observed. Lukita et al. [63] investigated the corrosion of wire mesh
in ferrocement specimen subject to simulated corrosive environments. Test results reveal that if
galvanized wire mesh is used a mortar cover of 3 mm could provide sufficient protection for
ferrocement structure subjected to marine environment. For ungalvanized wire mesh 4 mm
mortar cover is required.
The use of galvanized mesh to increase protection against corrosion is common. However,
Paul and Pama [64] and others warn of the danger of generation of hydrogen gas which causes
an expansive pressure on the surrounding mortar creating gas-filled voids. These voids cause a
deterioration of bond between the mortar and the mesh and an increased possibility of corrosion
through voids. loms [65] recommends the passivation of the mortar by the addition of 20 parts per
million of chromium trioxide to the mixing water; other authorities suggest lower or higher dosage.
Rengaswamy et al. [66] investigated the usefulness of rebar potential measurement. Their
396 Jownal of Ferrocemenl: Vol. 20, No. 4, October 1990
study included the influence of chloride ion concentration, moisture content, nature of cement
added and richness of the mix. They concluded that monitoring of reinforcement corrosion by
potential measurement is limited due to the influence of moisture content in concrete and the
tolerable limit for chloride is around 1,000 ppm by weight of concrete irrespective of strength of
concrete.
Kaushik et al. [67] also reported the long term corrosion performance of ferrocement structures
cast during the period from 1972 and 1987 and which were subjected to severe environmental
conditions of varying degrees. These structures have been continuously monitored for the incidence
of corrosion in the mesh reinforcement. Rengaswamy et al. [66], Chowdhury and Nimi-
tyongskul [68], Trikha et al. [69] and Kaushik et al. [67] investigated corrosion behavior of
ferrocement. Kaushik et al. [67] found that corrosion resistance of ferrocement elements 12 mm-
15 mm thick was excellent over a period of 14-15 years. Poor compaction and workmanship results
in microcracks in the structures increasing the corrosion rate appreciably. They recommended the
use of mechanical casting process, galvanized iron meshes, well graded sand for mortar, waterproof-
ing coatings and a minimum cover of 4 mm-5 mm for sound ferrocement structures.
Many old structures exist that still were built before any code provision was available or
even if available, proper utilization of the code was not made. Most of these structures are masonry,
usually constructed from brick or concrete blocks or in some cases stone. The problem becomes
more alarming if these structures are located in earthquake prone regions because in a seismic
event, the in-plane and out-of-plane horizontal loads resulting from the earthquake act on the
structure. But masonry structural components are solid planes which are designed primarily to
carry only the vertical loads within the structures. Therefore, they need strengthening to increase
their in-plane and out-of-plane shear capacity. Ferrocement has been employed for strengthening
structural elements like these. It has also found equal number of applications as a repair material,
in sewers, damaged beams, columns, etc.
In many repair or renovation program of civil engineering structures, ferrocement can be
suitably used as a repair or strengthening material due to several reasons [70]: (1) High levels
of performance in ductility, strength and other properties can be achieved even if quality control
is not up to standard; (2) Better cracking behavior; (3) Capability of improving some of the
mechanical properties of the treated structures; (4) Further modification or repair of
ferrocement treatment is not difficult; (5) Imposes little additional dead weight which
requires no adjusunent of the supporting structures; (6) Can withstand thermal changes very
efficiently; (7) Can achieve water proofing property without providing any surface treaunent; (8)
Can be used in repair program without any distortion or downgrading of the architectural concept
of the structure; and (9) Quite flexible for further modification.
Ferrocement has found tremendous applications for repair and strengthening of structures in
recent years. Recent researches were applied to walls, columns and beams in housing, sewers and
tunnels, boats, water tanks, swimming pools, concrete pavements and others.
Yuzugullu [71] investigated the use of ferrocement to increase the lateral resistance of
timber framed rural houses by means of thin ferrocement plates plastered on both faces. The test
results indicated the suitability of ferrocement in strengthening timber frames against lateral loads
such as earthquake, wind etc.
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 397
Ferrocement has also been applied for waterproofing and repairing leaking roofs in India.
Ferrocement was used for waterproofing the roof of Gandhi Bhawan Building in Chandigarh [72]
and Khatima Power House [73]. According to Markanda [72], ferrocement application on roofs cost
1.5 times lower than that of tarfelt treatment and at the same time would need lesser maintenance.
Strengthening and/or repair for masonry and concrete walls and columns were conducted by
Reinhorn et al. [74], Reinhorn and Prawel [75], Singh et al. [76], Balaguru [77] and Sharma and
Trikha [78]. Reinhorn et al. [74] and Reinhorn and Prawel [75] reported the suitability of a thin
ferrocement overlay as a seismic retrofit material for masonry walls.
Sharma and Trikha [78] recommended the use of ferrocement encasement for repair of fire
damaged concrete and masonry walls and columns while Singh et al. [76] reported the suitability
of ferrocement for strengthening brick masonry columns.
Balaguru [77] investigated the behavior of plain concrete cylinders confined in ferrocement
shells. He found that the wire mesh provided effective confinement, resulting in increase of
compressive strength and increase in ductility. The increase in the number of wire mesh resulted
in consistent increase in both strength and ductility.
The strengthening of reinforced concrete beams by encasing with ferrocement were studied
by Rosenthal and Bljuger [79], Lub and van Wanroij [80] and Anwar [81].
Rosenthal and Bljuger [79] investigated the flexural behavior of concrete beams encased in
ferrocement. They found that reinforced concrete beams encased in a ferrocement skin has shown
superior crack and strength performance compared to ordinary reinforced concrete beams. Lub
and van W anroij [80] strengthened existing beams in reinforced concrete building structures by
means of shotcrete-ferrocement. It was found that the wire mesh is fully effective and a monolithic
condition of the shotcrete layer and the original concrete beam is attained. The wire mesh was found
to act as excellent shear force reinforcement.
Anwar [81] investigated the use of ferrocement in the rehabilitation of beams. He studied
the effect of the amount of wire mesh and geometrical configuration of the ferrocement
encasement on the behavior of beams after rehabilitation. Encasement was done either at the
bottom only or on the three sides. It was found that rehabilitation of beams using ferrocement is
satisfactory and can be adopted practically.
Romualdi [82] discussed the application of ferrocement for infrastructure rehabilitation with
specific forms on relining of liquid containment structures, relining of tunnels and sewers and
rehabilitation of deteriorated structures and structures of insufficient seismic resistance.
Vickridge and Nedwell [83] have suggested design procedures for the ferrocement linings to be
used in repairing/rehabilitating existing sewers. Singh et al. [84] investigated the use of
ferrocement for renovating sewers. They performed an extensive theoretical, laboratory and field
testing programme undertaken in collaboration with the Water Research Engineering Centre
(U.K.) to help assess ferrocement and produce specifications and design procedures for in situ
coatings and precast linings for sewers. Attention was drawn to the need for type testing because
of the inadequacies of the mathematical methods for predicting crack widths. It was found that
the dominant criterion for design is steel stress related and not crack related. The system developed
has proved to be particularly adaptable for use in sewers with variations in alignment and cross
section. The conclusions drawn from the work have led to Ferro-Monk system being accepted and
classified as established system in ferrocement.
Paramasivam and Fwa [85] and Vasan et al. [86] investigated the use of ferrocement overlays
for repairing surface deteriorated concrete pavements. Paramasivam and Fwa [85] studied the
398 Journal o/Ferroceml!nl: Vol. 20, No. 4, October 1990
flexural behavior of beams constructed with three types of overlays - plain cement mortar, steel
fiber mortar and ferrocement overlays. It was found that ferrocement overlays exhibited superior
flexural performance than plain cement mortar and fiber mortar overlays, regardless of the types
of bonding provided.
Vasan et al. [86] investigated the use of ferro-fibro concrete overlays in concrete pavement
resurfacing. It was found that steel fiber reinforced ferro-fibro concrete can be advantageously used
as an overlay material. Overlay constructed with the composite matrix exhibits a significant
reduction in stresses, deflections and crack widths. It also distributes the cracks over a large
surface with the result that severity of damage to the pavement is reduced and the cracks remain
tightly closed even after ultimate load stage. The performance of overlay can be further improved
by using optimum fiber contents up to 1.25% by volume.
APPLICATIONS
Housing Applications
Ferrocement has found widespread applications in housing particularly in roofs, floors, slabs
and walls. Some researches were also made on the use of ferrocement in beams and columns.
Ferrocement roofs investigated included shell roofs, folded plates and channel shaped roofs,
sandwich panels, box girders and secondary roofing. Ferrocement shell roofs have been investi-
gated by Parameswaran et al. [87], Lakshmipathy et al. [88], Espiritu [89]. Jagadish and
Radhakrisna [90] and Kaushik et al. [91 ]. Lakshmipathy et al. [88] have performed an experimen-
tal investigation on the development of precast ferrocement panels for easy generation of cylindri-
cal shell. The precast panel developed was rectangular and singly curved (a portion of a cylinder).
The experimental investigation showed that the precast ferrocement panel was able to withstand
the required load carrying capacity and the developed shape can conveniently generate cylindrical
shells.
Espiritu [89] developed an interactive microcomputer program for the design of prestressed
ferrocement cylindrical shell roof. The program can analyze symmetrical cylindrical shells
under uniform loading for the following simple span cases: single barrel shells without edge beams,
if L/R > 5 and interior shells of multiple system, if L/R >2.
Kaushik et al. [91] investigated the behavior of ferrocement cylindrical shell units as roofing
elements and found that they can be used as roofing elements for low cost housing and satisfy
Indian requirements of loading, deflections and crack width with economy.
Parameswaran et al. [87] investigated the behavior of ferrocement groin roofing for single
story structures under the action of uniformly distributed load. Finite element analysis of the shell
using the SAP-IV program was also developed. The experimental results showed the excellent
performance of the shell roof even under the action of a load nearly three times the normal service
load for which such shell roofs are designed.
Jagadish and Radhakrishna [90] investigated the suitability and effectiveness of using ferroce-
ment hyperbolic paraboloid shell roofing units for short spans of 4 m. The results of the
experimental investigation showed that they are adequate. For low cost housing with short spans
up to 5 m, it was also recommended that, ferrocement hyperbolic paraboloid shells with two layers
of chicken mesh is quite adequate.
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 399
Folded plates and channel shaped roofing elements were studied by Kalita et al. [92, 93], Desai
and Desai [94], Kaushik et al. [95], Desayi et al. [96] and Jagannath and Shekar [97].
Kalita et al. [92, 93] found from an experimental investigation on segmental shell and
trough-shaped ferrocement roofing elements that the strengths of the elements are structurally
acceptable and can be adopted for low cost housing. The segmental elements are also found to be
more economical than trough-shaped elements.
Desai and Desai [94] studied the behavior of ferrocement trough, corrugated and folded plate
type roofing sheets and concluded that folded plate type ferrocement sheets exhibit more stiffness;
failure occurs by yielding of wires first followed by progressive fracture of the chicken mesh; and
the cost is 15%-25% less than the asbestos corrugated sheets.
Kaushik et al. [95] performed an experimental investigation on folded plates of spans 3.0 m
and 5.0 m. The experimental results compared well with the theoretical results, and a load
factor of 1.5 is recommended for ferrocement folded plate roofs.
Based from the results of an experimental investigation by Jagannath and Chandra Shekar
[97], it was found that the L-pan ferrocement precast roof element is suitable for low cost housing.
It satisfies the requirement of strength, stiffness and economy apart from being light, easy to
prefabricate and erect. Cost saving of about 39% can be attained compared to conventional rein-
forced concrete roof and an addition of 2% GI fiber reinforcement would be sufficient for low cost
fibrous ferrocement elements.
Desayi et al. [96] performed a study on roofing of a shed of size 5.73 m x 4.28 m using
pretensioned trapezoidal-section ferrocement elements. The elements were designed to carry a
live load of 1.5 kN/m 2 over an effective span of 5.5 m. Lintel cum chaija units over door and
window openings were also designed in ferrocement and used.
Other elements investigated for roofing are sandwich panels [98], secondary roofing slabs
[99, 100] and box girders [101, 102].
For floors and structural slabs, different researchers have undertaken theoretical and experi-
mental investigations and has recommended the suitability of the following:
* Cored slabs [103, 104, 105, 106]
* Precast ferrocement and reinforced concrete composite [107, 108]
* Slabs/plates [109, 110, 111, 112, 113, 114]
Researches on the application of fcrrocement to wall elements were done by Lee et al. [115],
Swamy and El-Abboud [116] and Yuzugullu [117]. The first two researches were on sandwich
wall panels and the third one on box wall elements.
Investigations on ferrocement columns were conducted by Rosenthal [118] and Chocka-
lingam et al. [119] while those on beams were conducted by Jiang [120] on T-beams, Desayi and
Ganesan [121] on I-joists, Desayi et al. [122] on prestressed T-beams, Desayi and Sudhakar Rao
[123] on beams with undulating flanges, and Al-Sulaimani and Ahmad [124] on I- and box beams.
Other Applications
Ferrocement applications to water resources structures are numerous. Ferrocement has been
used for:
* Water tanks [125, 126, 127].
400 Journal of Ferrocemenl: Vol. 20, No. 4, October 1990
CONCLUDING REMARKS
The paradox associated with ferrocement is that it is both the oldest and newest form of
reinforced concrete, and therefore, research needs comprise those common to conventional
reinforced concrete and those peculiar to ferrocement. The researches presented in this
keynote address represent only part of the researches done and ongoing to understand better the
behavior of ferrocement.
Ferrocement has gained widespread use and acceptance, particularly in developing countries
and has already attained worldwide popularity in almost all kinds of applications: marine, housing,
water resources and sanitation, grain and water storage, biogas structures, and for repair and
strengthening of structures. Widespread use of ferrocement is evident in countries like China,
U.S.S.R., India, Cuba, Southeast Asia and others. There are several reasons for its widespread
use. On the construction side: It can be fabricated into almost any shape; Skill needed for the
construction can easily be acquired; Heavy plant and machinery is not required; and Easy to repair.
On the material side, ferrocement possesses a degree of toughness, ductility, durability,
strength and crack resistance that is considerably greater than that found in other forms of
concrete construction.
However, there are still areas of applications where ferrocement is not widely used. This
may be due to insufficient understanding on the behavior of ferrocement. Hence, more
researches still have to be done. Lack of design codes is also one of the reasons. ACI has just
completed the "Guide for the Design, Construction and Repair ofFerrocement" [140]. U.S.S.R. and
China already have codes on ferrocement. And in other countries like Brazil, India and Cuba,
committees are now formed to prepare a code or design guide on ferrocement.
Ferrocement is still not known in some places. Technology transfer and information dissemina-
tion activities should be intensified to promote ferrocement technology and its applications. The
International Ferrocement Information Center (IFIC) and several international, government and
non-government institutions worldwide are actively promoting the use of ferrocement. Training
courses, seminars, conferences, symposia, and others are being conducted to help in the promotion
of ferrocement, aside from publications and researches.
Journal of Ferrocem£nl: Vol. 20, No. 4, October 1990 401
This keynote address only included some of the researches within the last 5 years. There are
actually more, both documented and non-documented, but it is not possible to cover all. But the
discussion here prove the many researches done on ferrocement and the future research thrusts on
ferrocement.
REFERENCES
48. Basunbul, I.A.; Nuh, S.M.; and Williamson, R.B. 1989. Fire resistance of fcrrocement
load bearing sandwich panels. Journal ofFerrocement 19(2): 109-123.
49. Swamy, R.N., and Spanos, H. 1985. Creep behaviour of ferrocement sections. In Pro-
ceedings of the Second International Symposium on Ferrocement, 103-118. Bangkok:
International Ferrocement Information Center.
50. Paillere, A.M. 1985. Durability and repair of fcrrocement. In Proceedings of the Second
International Symposium on Ferrocement, 673-679. Bangkok: International Ferrocement
Information Center.
51. Alexander, D. 1989. Factors influencing the durability of ferrocement. Journal of Ferro-
cement 19(3): 215-222.
52. Hope, B.B., and Ip, A.K.C. 1987. Corrosion of steel in concrete made from slag cement.
ACI Materials Journal 84(6): .
53. Shah, S.P.; Lub, K.B.; and Ronzoni, E. 1985. A summary of ferrocement construction and
a survey of its durability. RILEM Committee 48-FC, Materiaux et Constructions 19(112):
297-321.
54. Sri Ravindrarajah, R., and Paramasivam, P. 1986. Influence of weathering on ferrocement
properties. Journal ofFerrocement 16(1): 1-11.
55. Baseer, P.A.M.; Lau, D.K.T.; Montgomery, F.R.; and Long, A.E. 1988. Determination of
surface durability of ferrocement on site. In Proceedings of the Third International
Symposium on Ferrocement, 134-141. Roorkee: University of Roorkee.
56. Bowen, G.L. 1983. Corrosion and corrosion prevention in ferrocement hull. Journal of
Ferrocement 13(3): 267-268.
57. Bowen, G.L. 1987. Some thoughts about corrosion and corrosion prevention in ferroce-
ment boat. In Ferrocement Corrosion: Proceedings of the Correspondence Symposium.
Bangkok: International Ferrocement Information Center.
58. S. Carlos Group. 1985. Steel corrosion of fcrrocement: Some notes about older construc-
tions in S. Carlos, Brazil. In Proceedings of the Second International Symposium on
Ferrocement, 607-619. Bangkok: International Ferrocement Information Center.
59. Darwin, D.; Manning, D.G.; Hognestad, E.; Rice, P.F.; and Ghowrwal, A.Q. 1985.
Crackwidth, cover and corrosion. Concrete International: Design and Construction 7(5):
20-50.
60. Chalisgaonkar, R. 1987. Corrosion of steel in concrete and ferrocement. In Ferrocement
Corrosion: Proceedings of the Correspondence Symposium, 21-29. Bangkok: Interna-
tional Ferrocement Information Center.
61. Rengaswamy, N.S.; Srinivasan, S.; and Mohan, R.S. 1987. Evaluation of protective
coating for reinforced concrete. In Ferrocement Corrosion: Proceedings of the Correspon-
dence Symposium, 63-71. Bangkok: International Ferrocement Information Center.
62. lams, M.E. 1987. Prevention of fcrrocement corrosion. In Ferrocement Corrosion: Pro-
ceedings of the Correspondence Symposium, 91-93. Bangkok: International Ferrocement
Information Center.
63. Lukita, H.; Robles-Austriaco, L.; and Nimityongskul, P. 1987. Corrosion behaviour of
wiremesh in fcrrocement. In Ferrocement Corrosion: Proceedings of the Correspondence
Symposium, 3-19. Bangkok: International Ferrocement Information Center.
406 Journal of Ferrocemenl: Vol. 20, No. 4, Oclober 1990
64. Paul, B.K., and Pama, R.P. 1978. Ferrocement. Bangkok: International Ferrocement
Infonnation Center.
65. Iorns, M.E. 1984. Corrosion and corrosion prevention in ferrocement hull. Journal of
Ferrocement 14(2): 159-162.
66. Rengaswamy, N.S.; Balasubramanian, T.M.; Saraswati, N.; and Sarawathi, R. 1987.
Monitoring of reinforcement corrosion by potential measurement In Ferrocement Corro-
sion: Proceedings of the Correspondence Symposium, 31-53. Bangkok: International
Ferrocement Infonnation Center.
67. Kaushik, S.K.; Gupta, V.K.; Tiwari, V.K.; and Shanna, P.C. 1988. Corrosion perfonn-
ance of ferrocement structures 1972-1987. In Proceedings of the Third International
Symposium on Ferrocement, 142-152. Roorkee: University ofRoorkee.
68. Chowdhury, S.M.M.I, and Nimityongskul, P. 1985. Some aspects on corrosion of
galvanized wire mesh in ferrocement under simulated adverse environments. In Proceed-
ings of the Second International Conference on Ferrocement, 669-670. Bangkok: Interna-
tional Ferrocement Infonnation Center.
69. Trikha, D.N.; Kaushik, S.K.; Gupta, V.K.; Tewari, T.K.; and Shanna, P.C. 1985. Studies
on corrosion behaviour of ferrocement structures. In Proceedings of the Second Interna-
tional Symposium on Ferrocement, 621-632. Bangkok: International Ferrocement Infor-
mation Center.
70. Chowdhury, S.M.M.I, and Robles-Austriaco, L. 1986. Ferrocement for repair and
strengthening of structures. In Proceedings of the Asia-Pacific Concrete Technology
Conference '86, 20.1-20.15. Singapore: Institute for International Research.
71. Yuzugullu, 0. 1988. Ferrocement to increase the lateral resistance of timber framed rural
houses. Journal ofFerrocement 18(1): 35-39.
72. Markanda, P.C. 1985. Economics of ferrocement for waterproofing - A case study. In
Proceedings of the Second International Symposium on Ferrocement, 397-402. Bangkok:
International Ferrocement lnfonnation Center.
73. Ram, G., and Shanna, P.C. 1985. Ferrocement treatment for repairing leaking roof
gutters of Khatima Power House. In Proceedings of the Second International Symposium
on Ferrocement, 665-671. Bangkok: International Ferrocement lnfonnation Center.
74. Reinhorn, A.M.; Prawel, S.P.; and Zi-He Jia. 1985. Experimental study of ferrocement as
a seismic retrofit material for masonry walls. Journal ofFerrocement 15(3): 247-260.
75. Reinhorn, A.M., and Prawel, S.P. 1985. Ferrocement for seismic retrofit of structures. In
Proceedings of the Second International Symposium on Ferrocement, 157-172. Bangkok
International Ferrocement Infonnation Center.
76. Singh, K.K.; Kaushik, S.K.; and Prakash, A. 1988. Strengthening of brick masonry
columns by ferrocement. In Proceedings of the Third International Symposium on
Ferrocement, 306-313. Roorkee: University ofRoorkee.
77. Balaguru, P. 1988. Use of ferrocement for confinement of concrete. In Proceedings of the
Third International Symposium on Ferrocement, 52-58. Roorkee: University of Roorkee.
78. Shanna, P.C., and Trikha, D.N. 1988. Use of ferrocement for repair of fire damaged walls
and columns. In Proceedings of the Third International Symposium on Ferrocement, 580-
582. Roorkee: University ofRoorkee.
JourNJI of Ferrocem£n/: Vol. 20, No. 4, October 1990 407
79. Rosenthal, I., and Bljuger, F. 1985. Bending behaviour of ferrocement-reinforced con-
crete composite. Journal ofFerrocement 15(1): 15-24.
80. Lub, K.B., and van Wanroij, M.C.G. 1988. Strengthening of reinforced concrete beams
with shotcrete-ferrocement. In Proceedings of the Third International Symposium on
Ferrocement, 477-485. Roorkee: University ofRoorkee.
81. Anwar, A.W. 1989. Rehabilitation of Structural Elements Using Ferrocement. M.Eng.
Thesis, Asian Institute of Technology.
82. Romualdi, J.P. 1987. Ferrocement for infrastructure rehabilitation. Concrete Interna-
tional: Design and Construction, 9(9): 24-28.
83. Vickridge, I., and Nedwell, P. 1988. The current and potential use of ferrocement as a
structural repair material. Structural Engineering Review (1): 173-178.
84. Singh, G.; Venn, A.B.; Ip, L.; and Xiong, G.J. 1989. Alternative material and design for
renovating man-entry sewers. In Proceedings, NO-DIG 89: 2.3.1-2.3.7.
85. Paramasivam, P., and Fwa, T.F. 1988. Ferrocement overlay for concrete pavement resur-
facing. In Proceedings of the Third International Symposium on Ferrocement, 453-460.
Roorkee: University of Roorkee.
86. Vasan, R.M.; Godbole, P.N.; Kaushik, S.K.; and Goel, D.C. 1988. Performance evalu-
ation of ferro-fibro overlays. In Proceedings of the Third International Symposium on
Fcrrocement, 549-600. Roorkee: University of Roorkce.
87. Parameswaran, V.S.; Thandavamoonthy, T.S.; Balasubramanian, K.; and Mani, A.C.
1985. Ferrocement groin shell roofing for single storey structures. In Proceedings of the
Second International Symposium on Fcrrocement, 431-443. Bangkok: International Fer-
rocemcnt Information Center.
88. Lakshmipathy, M.; Kosalram, K.; and Ramakrishnan, S.S. 1985. A novel method of
generating cylindrical shells using precast ferrocement panels. In Proceedings of the
Second International Symposium on Ferroccment, 375-383. Bangkok: International
Ferroccmcnt Information Center.
89. Espiritu, E. 1987. An Interactive Microcomputer Program for the Design of Prestressed
Fcrroccmcnt Cylindrical Shell Roofs. M. Eng. Thesis, Asian Institute of Technology.
90. Jagadish, R., and Radhakrishna, K. 1988. Ferrocement hyperbolic paraboloid shell roof
clements - An experimental investigation. In Proceedings of the Third International
Symposium on Ferrocemcnt, 414-421. Roorkee: University ofRoorkee.
91. Kaushik, S.K.; Gupta, V.K.; and Mahendra Pal 1988. Investigation on ferrocement cylin-
drical shell roofs. In Proceedings of the Third International Symposium on Ferrocement,
537-543. Roorkcc: University ofRoorkee.
92. Kalita, U.C.; Nambiar, M.K.C.; Borthakur, B.C.; and Baruah, P. 1987. An investigation
on the strength of fcrroccment roofing elements for low-income housing. In Building
Materials for Low-Income Housing, 19-27. London: E. & F.N. Span Ltd.
93. Kalita, U.C.; Nambiar, M.K.C.; Borthakur, B.C.; and Baruah, P. 1985. Experimental
studies on ferroccmcnt roofing clements. In Proceedings of the Second International
Symposium on Ferroccmcnt, 405-413. Bangkok: International Ferrocement Information
Center.
94. Desai, J.A., and Desai, M.D. 1988. Ferrocemcnt roofing elements for low cost housing.
408 Journal of Ferrocement: Vol. 20, No. 4, October 1990
Material Properties
3916 Haynes, H.H.; Lawrence, F.K.; Stachiw, J.D.American Society of Civil Engineers.{Apr/
1971. Concrete Hulls for Undersea
Applications. Journal of Structural Division (514): 1283-1303.
concrete I domes(structuralforms) I hulls(structures) I offshore structures I shells(Structural Forms)
I Structural Engineering I Under water construction
Housing Applications
3932 Khaidukov, G.K. {197-. Development of armocement structures. Bulletin of the Infor-
mational Association for Shell Structures (36): 85-97.
ferrocement I roofs I shells (structural forms) I thin walled structures
412 Journal of Ferrocem£nl: Vol. 20, No. 4, October 1990
General
3897 lorns, M.E. 19-. Ferrocement-Does this Material Have Real Promise for Commercial Use?.
5 pp.
boats I corrosion I durability I low cost I mesh I mortar lpozzolana I yatch I Ferrocement
China I Cuba I England I New 'Zealand I USA I USSR
3888 Edwards, D.; Keller, K. 1982. (A) Workshop Design for Rainwater Roof Catchment
Systems. 76+iii pp.: Bureau for Science and Technology (Health Office).
construction I design I documentation I ferrocement /reports I tanks (containers) I training I water
storage
3866 United Nations Industrial Development Organization (Vienna, Austria). 1989. Non-de-
structive material testing. Advances in Materials Technology:Monitor, No.15, 118 pp. Vienna:
United Nation Industrial Development Organization.
ceramics I composite materials I heat I temperature !Nondestructive tests IX ray analysis
201-CONSTITUENT MATERIALS
3890 McCarter, W.J.; Afshar, A.B. 1985. A study of the early hydration of Portland cement.
Proceeding of Institution of Civil Engineers, Part II 79(September): 585-604.
cement paste I hardening (material) I hydration I microstructure I port/and cements
Journal of Ferrocement: Vol. 20, No. 4, October 1990 413
3867 Foy, C.; Pigeon, M.; Banthia, N. {1988. Freeze-thaw a durability and deicer salt scaling
resistance of a 0.25 water-cement ratio concrete. Cement and Concrete Research 18(4): 604-614.
compressive strength I corrosion Ifreeze-thaw durability I salt water! scale (Corrosion) I test I water-
cement ratio
3919 Cook, DJ.; Pama, R.P.; Darner, S.A. ( 1976. Rice husk ash as a pozzolanic material. In New
Horizons in Construction Materials, 431-442.
cement I chemical tests I pozzolans I rice husk ash I strength I strength I volume change Developing
Countries I Thailand
3877 Spence, R. 1987. (A) field guide to the use ofpozzolana as an alternative cement. Gate (2):
11-14.
cements I mixing I mixing I port/and cement I pozzolana I production
3862 Day, R.L.; Huizer, A.; Quinonez, J. 1989. Mortar and grout for masonry units produced from
natural pozzolanas. Housing Science 13(4): 283-289.
blocks I clays I low cost I masonry I mortar I pozzolana Bolivia I Canada I Guatemala
Admixtures
3935 Rohm & Hass Company (Pennsylvania, U.S.A.). 1967. Rhoplex E-330 Cement Mortar
Modifier. 7 pp. Pennsylvania: Rohm & Hass Company.
admixtures I freeze traw durability I mortar I physical properties
301-MARINE APPLICATIONS
3931 Fyson, J.F.{1968. Ferrocement Construction for Fishing Vessels .. 8 pp. London: Food
and Agricultural Organization.
boats I construction I design I ferrocement I mixing I properties I ships
414 Journal of Ferrocement: Vol. 20, No. 4, October 1990
3933 Gardner, J. 1968. Ferrocement moves from backyard to shop - New methods are required in
production. National Fisherman (October): 2 pp.
barges I construction I fabrication I ferrocement
3902 Jay R. Benfordand Associates, Inc. (Washington, USA). 1971. Design and Services. 1-15.
Washington: Jay R. Benford and Associates, Inc ..
boats I construction I costs I design I ferrocement I ships I specifications
3869 Kerr, R.N. 1972. Requirements for the construction of ferrocement boats. Hull
Construction, 7 pp. Wellington: Marine Department.
applications I boats I coatings I construction I design I ferrocement I mixing I standards
3925 Robertson, A. 1975. One man's plastering. News Bulletin (31): 4-5.
boats I ferrocement I plastering I scaffolds
Australia
3889 Mahati, L. 1978. Ferrocement dreams part 6. Sea Worthy Dreams 3(1): 39-44.
boats I construction I ferrocement I hull (structures) I plastering I schooners
3926 Bowen, G.L. 1984. Seven Years oflife aboard a ferrocement boat. Ferro-Cement Commu-
nique (1): 1-7.
boat I ferrocement I hulls (structures) I plastering
New Zealand
3907 New Zealand Ferro-Cement Marine Association, Inc. (Auckland, New Zealand).1985.
Materials, methods and maintenance. Ferro Cement Communique (2): 11-13.
boats I construction I maintenance I production methods I repairs
3901 Mullins, A.F.J.1970. Power for small boats ... Massproduction canmeettheneed. Fishing
News International : 79-83.
advantages I applications I boats I ferrocement I ships I trawlers
Developing countries I Sri Lanka
Journal of Ferrocemen/: Vol. 20, No. 4, Oc/ober 1990 415
3927 Turner, J. 1979. Observations on ferrocement in the marine industry. Ship Boat Interna-
tional : 52-53.
boat I corrosion I ferrocement I hull (structures) I workability
3910 New Zealand Ferro-Cement Marine Association, Inc. (Auckland, New Zealand).1985.
Is ferrocement a proposition?. Ferro Cement Communique: 24-28.
advantages I boats I ferrocement I ships
General
3894 Ministerio De la Industria Pesquera (Havana, Cuba). 198-. Catalogo general de proyectos
construidos. 200 pp. Havana: Ministerio de la Industria Pesquera.
boats I properties I specifications I vessels
3915 Hagenbach, T.M.Seacreted, Ltd. (Norfolk, UK). 1971. Top Seacrete. 4 pp.
advantages I boats I ferrocement I hulls (structures) I properties
3917 Fiber Steel (West Sacramento, California, USA). 1971. Fiber Steel Progress Report. 11 pp.
West Sacramento: Fiber Steel.
boats I hulls (Structures) I ships I Ferrocement I Yacht
3918 Food and Agricultural organization of the U.N. (Rome, Italy). 1973. Seminar on the
Design and construction ofFerro-CementFishing Vessels. FAO Fisheries Report, 27pp. Rome: FAO
boats I construction !fiber reinforced composites I steel structures I wooden structures I Ferrocement
3908 New Zealand Ferro-Cement Marine Association, Inc. (Auckland, New Zealand).1985.
Inspection of ferro boats before plastering. Ferro Cement Communique (2): 14-15.
boats I inspection I performance I quality control I standards
3909 New Zealand Ferro-Cement Marine Association, Inc. (Auckland, New Zealand). 1985.
Ferrocement in boat building. Ferro Cement Communique (2): 16-18.
applications I boats I construction I ferrocement I hulls I strength
416 Journal of Ferrocemenl: Vol. 20, No. 4, October 1990
3923 Southern Ports Shipbuilding Co., (Iran). Builders in Ferrocement, Corrosion and
Maintenance.
boats I construction I corrosion I design I fire resistance I impact I maintenance I Ferrocement
3924 Hammond, A. Feb/1972. Ferrocement Rachel and Ebenezer to be coasting schooner replica.
National Fisherman (Feb.): 3 pp.
boats I bulkheads I construction I ferrocement I schooners
401-TERRESTRIAL APPLICATIONS
3879 Structural Engineering Research Center (Madras, India). 1980. Ferrocement service
core units. Journal of the Institution of Engineer (India) 30(3): 1 p.
construction I ferrocement I housing I mesh I mortars (Material) I walls India
3891 National Economic and Social Development Board (Bangkok, Thailand). 198-. Manual
for the Construction of Cement Jar. 10 pp. Bangkok: National Economic and Social Development
Board.
construction I manuals I mortars (material) I production methods I water storage
Thailand.
3895 Thailand Institute of Scientific and Technological Research (Bangkok, Thailand). 1977.
Construction of Ferrocement Structure (Construction of Water Tank). 13 pp. Research: Thailand
Institute of Scientific and Technological Research.
construction I ferrocement I production methods I water tanks
Journal of Ferrocem£nl: Vol. 20, No. 4, Oclober 1990 417
3874 Development Information Center (Washington, DC., USA). 1982. Designing a household
cistern. Water for the World Technical Note, No. RWS. 5.D.1., 8pp. Washington: Development
Information Center.
design I ferrocement I specifications I tanks (containers) I water storage
3884 Bingham, A. 1984. Modular approach for Indonesia's national programme. World Water
(August): 31-32.
housing I water I water pipes I water supply Indonesia
3876 Webber, E.S. 1985. Rainwaterroof collection as a household water supply. In South Pacific
Regional Worshop on Housing, 1-7.
construction materials I design I roofing I water I water storage I water supply
3868 AIT Alumni Association (Thailand). 19-. Construction Manual of a Ferrocement Tank.
48 pp.: AIT ALumni Association (Thailand).
construction I costs I design I ferrocement I tanks
Miscellaneous Structures
3930 _ _ . 1979. Wire panel combines benefits of wood, concrete. California Builder & Engineer
(Nov.): 85-86.
concrete I panels I sound transmission I warehouses I wood I Prefabrication IFIC
3906 New Zealand Ferro-Cement Marine Association, Inc. (Auckland, New Zealand).1985.
Ferrocement as a sculptural material. Ferro Cement Communique (2): 9-10.
advantages I applications I ferrocement
3863 Singh, G.; Venn, A.B.; Ip Lilian 1989. Alternative material and design for renovating man-
entry sewers. No-Dig: 1-4.
applications I crack width I ferrocement I precast concrete I sewers I stress concentration
UK
Construction Techniques
3900 Fyson, J.F. 1970. Building a Sawn Frame Fishing Boat. FAO Fisheries Technical Paper
No. 96, 54+IV pp.
boat I construction I drawings I frames I ships I specifications
418 Journal of Ferrocemenl: Vol. 20, No. 4, October 1990
3886 Singh, S.M.; George, J.{ 1984. Cement paints. Building Research Note, 3 pp. Roorkee:
Central Building Research Institute.
coatings I durability I finishes I paints I protective coatings
3921 Sambell,R.A.S.;Bowen, D.H.; Philips, D.C.1972. Carbon fibre composites with ceramic
and glass matrices - Part I Discontinous fibres. Journal of Material Science (7): 663-675.
carbon fibers I ceramics I glass I properties
Polymer Composites
38% Choy, C.L. (ed)1984. High Modulus Polymers and Composites. 395 pp. Hong Kong: The
Chinese University Press.
composite materials I composites I creep properties I fatique (materials I fiber reinforced I
mechanical properties I modulus of elasticity I polymers I strength I toughness
Journal of Ferroceml!nt: Vol. 20, No. 4, .October 1990 419
General
3882 Balaguru, P.N.; Shah, S.P. {1985. Alternative reinforcing materials for less developed
countries. International Journal for Development Technology 3: 87-105.
bagasse I bamboo I bending I bonding I coconut fibers I columns (supports) I compression I
ferrocement I housing I jute fibers I low cost I natural fibers I properties I sisal fiber I slabs I tension
Africa I Australia I China I Developing Countries I Europe I India I Philippines I Thailand
3885 Ji, Xing; Liu, Xi-Rui; Chou, Tsu-Wei 1985. Dynamic stress concentration factors in
unidirectional composites. Journal of Composite Materials 19(May): 269-275.
dynamic characteristics I fiber reinforced composites I numerical analysis I stress concentration
3899 _ _ . 1987. Fibermesh - a plastic solution. New Zealand Concrete Construction 31: 21-24.
bleeding (concrete) I crack initiation I toughness I Fiber reinforced composites
New Zealand
701-GENERAL
State-of-the-Art Studies
3937 ACI Committe 549. 198-. State-of-the-Art Report on Ferrocement. 90+iii pp. Detroit:
ACI
construction materials I crack spacing I crack width I ferrocement I impact I mechanical properties
Technology Transfer
3870 Robles-Austriaco, L.; Pama. R.P. 1981. Technological transfer - Demand, transfer,
diffussion: The case for construction materials. In Proceedings of the International Symposium on
Technological Tranfer - Demand, Transfer, Diffusion, 1-22.
applications I construction materials I ferrocement I prestressed concrete I technology transfer
3936 Nimityongskul, P.; Choeypunt, C.; Karasudhi, P.{ 1981. Ferrocement Field Evaluation
Survey in Indonesia. 57+iii pp. Bangkok: Asian Institute of Technology.
applications I ferrocement I surveys I technology transfer I trainings
Indonesia
800-Related Materials
3911 Portland Cement Association (Chicago, USA). 1951. Concrete Grain Storages for the
Farm. 16 pp.: Portland Cement Association.
bins I concrete structions I grain storage I silos
420 Journal of Ferrocement: Vol. 20, No. 4, October 1990
3914 Portland Cement Association (Illinois, USA). 1965. Handbook for Concrete Fruit and Vege-
table Storages. 13 pp. Illinois: Portland Cement Association.
concrete I construction I food storage I panels I roofs
3913 Portland Cement Association (Illinois, USA). 1970. Design and Construction of Concrete
Feedlots. 8 pp. Illinois: Portland Cement Association.
concrete I construction I design I pavements I slabs
3880 Kanok-Nukukhai, W.; Karasudhi, P.; Nishino, F.; Brotton, D.M.Advances and practice
in East Asia and the Pacific. In Proceedings of the First East Asian Conference on Structural
Engineering and Construction. Bangkok: Asian Institute of Technology.
bridges I buildings I computer programs I computers I concrete I construction I construction
methods I design I ductility I foundations I reinforced concrete I stability I strength
4084 Ellen, P .E. 1985. Concrete mix design - Basic philosophy. Lecture Notes, Short Course on
Design and Construction of Ferrocement Structures, 207-241. Bangkok: International Ferrocement
Information Center.
concrete I mix design I water cement ratio I micro cracks
4086 A pens, J. 19-. Binders, Alternative to Portland Cement. Lou vain: ATOL.
port/and cements I cements I materials
4087 International Ferroccment Information Center. 1990. Ferrocement Floating House Project,
Executive Summary. Bangkok: International Ferrocement Information Center.
housing I ferrocement I construction I /owcost
Journal of Ferroceffll!nl: Vol. 20, No. 4, October 1990 421
The INFC and IFIC databases will save your time and effort in finding current information on
ferrocement and related construction materials. These databases are created and maintained by the
International Ferrocement Information Center (IFIC), Asian Institute of Technology, Bangkok,
Thailand using UNESCO's Computerized Documentation Service/Integrated Set of Information
Systems (CDS/ISIS).
The highly specialized construction materials included in the databases are directed to answer
the needs of the low-income people in the developing countries. They cover ferrocement, the
form of reinforced concrete which uses hydraulic cement mortar, and closely spaced layers of
continuous and relatively small diameter wire mesh reinforcements; and related construction
materials, such as steel fiber composites, bamboo fiber composites, natural and organic fiber
composites, and polymer composites.
IFIC regularly reviews over 100 journals, magazines, newsletters, digests and bulletins, in
addition to numerous monographs, reports, conference proceedings, theses, and materials supplied
directly by ferrocement builders and researchers. From these publications, articles on ferrocement
and related construction materials are identified, abstracted, indexed, and entered into the
bibliographic databases.
Each record contains primary information: author, title, source, abstract and keywords; and
secondary information: availability, date, language and type of publication.
INFC and IFIC databases contain over 3,500 records and these are expanding at the rate of
300 records per year. From these records, IFIC provides computerized bibliographic search
services for requests on particular aspects of ferrocement technology and related materials at the
following rates:
Precise description must accompany requests for search service so as to minimize costs.
Requests (particularly for letter and telex requests) must include the following: (a) brief but clear
summary of the research topic; (b) list of keywords and synonyms; (c) expected number of
references; (d) cost limitations; (e) output specifications (date and language restrictions); and
(f) degree of urgency of the request. The search print out contains a list of references, which may
include abstracts if requested.
Materials listed in the bibliographic search print out are available from IFIC, but subject to
copyright restrictions. By quoting the accession number given at the top of each reference,
photocopies and/or microfiches of any document can be ordered at the rates given in page 446.
JourNJJ of FtrroctrMnt: Vol. 20, No. 4, October 1990 423
The first ferrocemenl boat constructed al ITB in 1977 e.xhi~ Ferrocemenl Mural, the main gale of the Indonesia Mini-
iu no corrosion and structural defecu. atu~ Parle.
424 JowNJJ ofFt"oceme/IJ: Vol. 20, No. 4, October 1990
A ride in "Ganesh&" a fenocement fishing boll. The tidal gate at Lampl.Rig Shrimp fann.
JOllTlllJi of Ftmx:tmenJ: Vol. 20, No. 4, October 1990 425
courses.
The participants were impressed by the vari-
ety of projects and the effectiveness of the trans-
fer of technology.
Among the recommendations of the partici-
pants were:
- Preparation ofa methodology for end users
training; a primer for decision makers; and audio-
visual material.
- Three layer approach Lo technology trans-
fer.
- Establishment of local national standards
on ferrocemenL for the Optimisation of Prestrenssed Concrete
- Standardize management structure for all Box Girder Bridges."
national nodes. Engr. Gregorio T. Estrada, (above) regional
technical director, Environment and Protected
Areas Service, Department of Environment and
VISITORS AT IFIC Natural Resources, Region XI, Davao City. Phil-
ippine, visited IFIC and discussed fcrrocemcnt
Dr. K. Ghavami (below lefl) is a professorof applications for his projects.
Civil Engineering at the Pontificia Universidade Mr. Hans Hcijnen (below) senior informa-
Catolica do Rio de Janeirio and resource person tion officer of the International Reference Centre
of the IFIC Reference Center at the University. for Community Water Supply and Sanitation
He auended an IDRC Meeting in Singapore and (IRC), the Hague, the Netherlands, visited IFIC
visited AIT on 17 September 1990. He con- recently. For the last seven years, he was as-
ducted a Seminar on Non-Conventional Con- signed to Nepal and Sri Lanka as project manager
struction Materials. of water supply and sanitation projects. During
Dr. D.N. Trikha (below right) is a professor this tenure, he successfully addressed informa-
and Head of the Department ofCivil Engineering tion issues as they arose at the project level by es-
at the University of Rookee, India. Dr. Trikha is tablishing and maintaining an extensive project
also editorial board member of the Journal of library on appropriate levels of rural water supply
Ferrocement and co-coordinator of the Fcrroce- and sanitation, by encouraging the publication of
ment Information Network (FIN) India. technical manuals on vernacular and by enabling
Dr. Trikha conducted a seminar on 18 Sep- the introduction and applications of new ideas
tember 1990on "lntegratedFEM-SLPApproach such as the use of ferrocement.
426 JourNJ/ of Ft"ocemen.1: Vol. 20, No. 4, October 1990
visited the exhibition. Ferrocement covered the zation. Copies of this video can be purchased
largest floor area in the display. IFIC publications from: Duffill Watts & King, PO Box 5269,
were displayed in a separate section and IFIC Dunedin, New 'Zealand. Phone 777-133.
activities were explained to the visitors. (Source: Hudson, K.C. 1990. Pavements
(Information from Mr. P.C. Sharma, Scien- Engineer, Cement & Concrete Association)
tist, SERC Ghaziabad, /ndia).
Diamond Wire Saw - The In-depth Solution
Further information and application forms greater understanding and knowledge of all as-
are available from the C&CA, Private Bag, pects of structural and architectural concrete.
Porirua, New 'Zealand. Entries must be of projects substantially
completed within the last two years. For the
The Joint For Quality Floors Concrete Award they should illustrate a signifi-
cant achievement in the advancement of concrete
practice in design, research, construction or
The weakest part of concrete floors are the
rehabilitation of any work.
joints. The joints are often submitted to high
repetitive loads and stresses causing damage and In respect of the Prestressed Concrete
high maintenance costs. Award, entries should be of projects in which
prestressed concrete fulfils a major role in its
1REMIX have developed a precastconcrete
structural performance and/or visual appeal.
joint that solves many of the problems that design
engineers and owners face today. The 1REMIX All entries accepted for judging in the
TreForm Rail is cast into the floor. The high Awards will be published in the October issue of
strength concrete joint minimises the risk of the journal of New Zealand Concrete Construc-
damage to the finished floor. tion. This will give projects and those associated
with them wide publicity throughout New Zeal-
The 1REMEX TreForm allows production
and and also in many overseas countries.
of finished floors that have high flatness toler-
ances. The TreForm acts as a screed rail which is Entry forms and rules for the Award are
levelled to the finished floor surface. The Tre- available from the NZCS, PO Box 17-268
Form replaces conventional wood and steel Wellington, New 'Zealand.
forms and end stops.
1REMIX TreForm rails are an integral part Robots Assist With Beam Assembly
of the 1REMIX system of laying high quality
concrete floors. The full method involved dewa- Taisei Corporation of Tokyo has developed
tering concrete by the vacuum process, thereby a robot for automatically assembling beam rein-
reducing excess water and decreasing the water/ forcing bars for reinforced concrete buildings
cement ratio known as the TRFR-01 (Taisei Reinforcingbar
For further information Fabricating Robot).
Ready Mixed Concrete Ltd. When the robot was used to make 1000
PO Box 282, Hamilton beam reinforcing bars for the B building of the
New 'Zealand Okawabata River City 21 in Tokyo, it increased
Tel. (071) 492889 production efficiency by 50% compared to
FAX. (071) 491291 skilled manual labor.
The mobile cart is operated by one worker
and assembles the reinforcing bar while moving
N.Z. Concrete Awards
on the rails. The reinforcing bar is assembled in
the following order:
The New Zealand Concrete Awards, are
now open for submission of entries for the 1990 1. The main reinforcing bars are set on
scheme. the upper and lower main reinforcing bar support
arms.
The Awards the Concrete Award and the
Prestressed Concrete Award, offered and run by 2. The stirrup bars are set inside the
the New Zealand Concrete Society, are designed mobile cart.
to further its principal aim of encouraging the 3. The type of reinforcing pattern is se-
430 Journal of Ferrocemen.I: Vol. 20, No. 4, October 1990
lected by pushing the selection button on the solution of the problems of arid regions in Paki-
control panel. The automatic operation button is stan for the last twenty five years. The variety of
then pushed. aspects of their area of work includes tree planta-
4. The mobile cart moves forward, and tion, drip irrigation, fodder development, water
while setting the stirrup bars, automatically binds pumping, windmill installation in the desert area
the stirrup bars to the upper main reinforcing and the use of surplus water. Merin Ltd. have at
bars, one after the other. their disposal a small experimental farm where
numerous tests with many crops under varying
5. After all the stirrup bars have been
conditions are performed. The organization is
bound to the upper main reinforcing bars, the
now able to present on a commercial basis, under
lower main reinforcing bar support arm.
operating conditions, a variety of equipments and
6~ While moving backward, the mobile systems which are focussed on the target of
cart automatically binds the stirrup bars to the producing profitable utilization with minimal
lower moves downward main reinforcing bars water supply and using local resources. A new
one after the other. term 'OFIT has been coined to represent this
7. When the setting and binding of all the combination of organic farming and intermediate
stirrup bars has been completed, the completion technology. Ferrocement is also use as of the
lamp is lit to inform the operator. construction material in the farm for biogas plant,
The following are the main features of the well lining and others.
Taisei-developed robot
I . The entire fabrication process can be PHILIPPINES
carried out by one operator, who need not be a
skilled rebar worker. Ferrocement Boats Come of Age in the Philip-
2. High product quality can be main- pines
tained.
The l 980's saw unprecedent increase in the
3. The stirrup bars are set and bound to
costs of building ships for various purposes like
the reinforcing bars automatically.
pushing, passenger ferites etc. The escalating
4. The binding wire is automatically prices of building new ships, led most of the
supplied from a reel. probable owners to look for used second hand
5. The robot can handle several types of boats rather than attempting to build new ships.
reinforcing patterns. Keeping the situation in view, the government of
On the basis of the technology used in devel- the Philippines has been making efforts to bring
oping this robot, Taisei will carry out research to about economic stability to local ship building
develop a completely automatic production line industry by establishing joint venture type pro-
for columns and beams in prefabrication plants. grams for ship building with developed coun-
tries. The government of the Philippines also
(New Zealand Concrete Construction, April
1990)
made efforts to encourage the promotion of new
methods and construction techniques in ship
construction. A part of this promotion scheme is
PAKISTAN to encourage the development of non-conven-
tional ferrocement vessels. The ferrocement
Organic Farming and Intermediate Technol- boats are not only low cost in construction but
ogy have proved to save on repair costs also compared
with conventional ship construction. Plans and
Merin (Pvt) Limited has been engaged in the detailed specifications are developed and distrib-
Journal of Ferrocement: Vol. 20, No. 4, October 1990 431
uted under this program to construct ferrocement blocks has been implemented and promoted as
boats, 30 ft (9.15m) in length, to be used as low cost building materials in rural areas by many
passenger boats. the vessel has a capacity to carry government agencies under the supervision of
40 passengers. A detailed report has been pre- TISTR. The plain or solid blocks have been
pared with emphasis on practical aspects of ferro- modified to become interlocking blocks aiming
cement boat construction, covering all details to achieve more structural stability and aesthetic
right from outlining to the final finishing opera- sense.
tion. Using the guidelines in the report, the In 1986, the stabilized soil cement block has
construction of a model ferrocement vessel was been recognized as a suitable building materials
started on July 15 of this year at Sandoval Ship- for government staff housing application by the
yard and the overall configuration of the reinforc- Budget Bureau, Prime Minister Office, accord-
ing structure was completed on September 30. ing to the Civil Work Department's public hous-
Periodic inspection by Marina counter part (the ing standards.
organization to promote ship building), main-
BTD conducted a three-year jointly coop-
tained a schedule of systematic inspections to
erative research project with Government Indus-
ensure that the construction of the vessel is in
trial Research Institute, Kyushu (GIRIK), Japan.
accordance with the specified rules and regula-
The main research activities are as follows:
tion of the American Bureau of Shipping (ABS),
and internationally recognized classification a) Survey and assessment of agro-wastes
society. The vessel is expected to be launch soon. and relevant materials.
(lnformationfromEngr. Jose Ariel L. Bala- b) Quality improvement of raw materials.
sabas, Sr. Shipbuilding Specialist, Engineering c) Investigation on the utilization of agro-
Research and Development Division, Technical wastes for building materials.
Services Office, Maritime Industry Authority, d) Techno-economical assessment of the
Philippines). production process and products.
Research results so far can be summarized
as follows:
TIIAILAND 1. Each year some 4 million tons of rice
husk, one of the agro-wastes abundantly avail-
Research and Development at Thailand Insti- able in Thailand, i.e. about 20 percent of the total
tute or Scientific and Technological Research paddy crop, remain after the rice is processed for
(TISTR) and Building Technology Depart- consumption. A small amount of this husk is up
ment (BTD). to use as cattle fodder, fuel, etc. So far, it has been
a waste material posing difficult problem of dis-
TISTRandBTD has recently been conduct- posal everywhere it is produced.
ing research on low cost building materials 2. When rice husk is burnt, about 20% by
through utilization of waste and natural re- weight of the husk remains as ash which is
sources. characterized by high Si02 content The si02
Utilization ofWaste and Natural Resources. content of Thai rice husk ash generally exceeds
Two separate studies have been made on 90% by weight when the husk is well burnt.
low cost building materials. One of them deals 3. Rice husk ash (RHA) retains the skeleton
with agro wastes (e.g. rice husk, com-cob, etc.) of celluar structure, which makes its porosity and
and the other with indigenous resources (lateritic surface area high. Amorphosity of RHA can be
soil, cement blocks, bamboo, low-grade wood controlled by varying burning conditions. The
etc.). Result of the study on stabilized soil cement lower burning temperature and shorter burning
432 Journal of Ferrocement: Vol. 20, No. 4, October 1990
period give amorphous silica. the higher tem- develop the appropriate construction technology
perature and longer period of burning accelerate for constructing the house of low-medium in-
its crystallization into cristoblite and tridymite. come people in urban area, in order to make the
4.RHA cement can be produced by mixing use of building materials more efficient and
ground RHA with lime and/or portland cement. lower the cost of construction and materials.
Silica contained in RHA reacts with lime in the Also,ademonstration house of two-story is being
presence of water to fonn calcium silicate hy- built at TISTR complex, to illustrate the utiliza-
drates which function as binder in RHA cement. tion of the building component manufactured
When portland cement is used lime liberated locally and the application of new building
during hydration reacts with silica in RHA. Since component developed by BTD, such as window
RHA cement hardens mostly at ambrient tem- and door frame, stair case and purlin. The basic
perature, calcium silicate hydrates thus fanned material for such components are concrete.
remain in amorphous or poorly crystalline stages Implementation of Research Findings
which are identifies as C-S-H and C-S-H(I). Following the success of TISTR's research
5. When the reaction of silica and lime takes into the development of low-cost materials for
place in an autoclave under a saturated steam housing construction like soil cement blocks,
pressure at elevated temperatures ranging fonn several other cooperative projects were also
l 70"C too 200"C, well crystalline calcium silicate undertaken during 1987-1989. These included
hydrates are obtained such as xonotlite (C6S6H) the low-cost rural demonstration house project in
and llA tobennorit (C5S6H5). Such reaction is C,humpuang District, Nakhon Ratchasima Prov-
know as hydrothennal reaction. Xonotlite and ince, which was carried out with AIT and PGCHS
tobennorite constitute a matrix of calcium sili- University of Leuven, Belgium in 1987.
cate insulation materials, which can be widely For 1988 and 1989 TISTR worked with the
use in industry for energy saving and in construc- Military Forces of Prachin Buri Region and the
tion of highrise buildings for fire-proofing. rural people in the area to build a Children's
6. Replacement of rice husk ash by ground Daycare Center. In this project, TIS TR had the
quartz is possible to a certain extent to obtain well opportunity to train the rural people and military
developed xonotlite crystals in size. In this case, personnel in low-cost construction techniques by
the reaction conditions, such as the mixing ratio using soil cement blocks.
with lime, the reaction temperature and time,
should be chosen experimentally to reach the
optimum preparation. U.K.
Development of Bamboo for House con-
struction. Measuring Loads on Staircases
The project was the application of bamboo
Data for the actual loads exerted by people
for house construction by using simple technol-
on stairs, balconies and handrails will soon be
ogy for rural people. A simple method used in the
available as the result of full-scale tests commis-
project is named bamboo lath and plaster, The
sioned by BRE. The figures currently given in the
plaster is the mixture of lime, sand, and chopping
main structural loading code (BS6399 Part 1) and
rice straw added up with water under the specific
the code for protective barriers (BS6180) are
process. The bamboo lath with both sides plaster-
based on assumptions and have not previously
ing can be applicable as a durable external panel.
been fully checked against practice. Recently
Research and Development of Housing there have been conflicting criticisms about the
Construction Technology on Industrial Scale requirements for loading by people, some groups
The objective of this research is to find and claiming that the loads were too high, others that
Journal of Ferroceml!nl: Vol. 20, No. 4, October 1990 433
with a minimum calcium carbonate content of Sculptures, Irish Concrete Society Awards
75% by mass.
To provide data on the effects of limestone The following four concrete sculptures by
fillers on concrete performance in UK condi- Irish artists were submitted for the 1989 Award.
tions, BRE re-convened a Working BRE Party, "A Walk Around Stone", by MichaelBulfin,
originally set up in 1974, involving BRE the is situated on the left shoulder of an approach
British Cement Association, and cement manu- road to the Ballymum round-about, and was
facturers. The Working Party set up a substantial designed for that specific site. Artistically, the
research program to examine the effects of fillers concept is of a modem day megalithic stone
on cement properties and on the strength and alignment contrasting man-made stone with the
durability of concrete. natural granite which the original inhabitants
The findings so far are: used, and of which there were many examples in
the Ballymun-Finglass area before building be-
- Concretes made from cements containing
gan.
up to 50% of limestone filler are virtually indis-
tinguishable from traditional OPC concretes. The piece, believed to be the largest con-
crete sculpture in Ireland, is also designed as a
- Strength for strength, concrete made from
children's play sculpture with seats, steps, King-
cement with 20% filler has a carbonation rate
of-the-Castle detail, and niches in the concrete
similar to pure OPC concrete. However, these
elements for hide-and-seek. Weight of the largest
cements have lower 28 day strength than OPC
concrete element is 9 tons, and of the larges
and higher cement contents will be needed to
granite element, 12 tons.
achieve equivalent strength. Thus specifying
only minimum cement content and maximum Katy Goodhue, who works mainly with
water/cement ratio, as proposed in the European animal forms and often on a large scale, has
prestandard for concrete ENV206, will not guar- produced "Watchdog", using concrete because it
antee durability in concrete containing fillers: the is not expensive and needs little equipment to
specification should also include minimum produce a strong durable finished piece. An
strength grade. armature of welded mild steel bars incorporating
fixing points to which expanded metal is securely
- In laboratory freeze-thaw tests, filler-
attached, provides the framework for the piece,
cement concretes do not perform so will as OPC
the shape of which is resolved using a 4: 1 sand
concrete unless they are air-entrained, which
and cement mix applied by trowel and spatula.
would normally be recommended in practice.
"Watchdog" is to be found at Femhill Gar-
- Permeability is generally lower than in
dens, Sandyford, Co Dublin, and is described by
non-filler concretes.
the artist as illustrating "a decorative use of con-
- Sulphate resistance depends primarily on crete in a natural environment."
the composition of the parent cement
The sculptor for "Aquaduct", a fountain-
- Data on depth of chloride penetration are type water piece in white ferrocement, is Niall
inconclusive so far. O'Neill. The five upright forms, in Nutley
For more information, contact Square, Donnybrook, Dublin, are arranged in a
BRE Technical Consultancy spiral configuration, each form at right-angles to
Carston, Watford WD2 7JR the next and diminishing in height from the
(Tel: 0923 664800) tallest, at 7ft (2.13m) high, to the smallest, at 4ft
Journol of Ferrocem11nl: Vol. 20, No. 4, October 1990 435
(1.22m). Water is pumped up the tallest column, Polarii.ation Resistance Measurement (LPRM)
bubbles out the top and flows in a stream drop- technique. Applying a small over-potential to the
ping from form to form. It then drops into a rebar and measuring the resultant current indi-
central pool and flows out into the outer pool, cates the corrosion condition relative to other
where it is pumped back up again. areas. Using a conversion factor gives an esti-
The concept in this piece is that there should mate of the corrosion rates.
be a combination of auditory and visual sensa- Although this method has been used before,
tions. For example, on a sunny day the sun on the Dr. John believes that CAPCIS' applied research
water is reflected on waved patterns up the sides has eliminated some of the previous pitfalls of
of the columns, to the sound of the water splash- LPRM. The biggest problem has been to achieve
ing and cascading down the piece. an electrically conductive path through the con-
Niall Walsh explains that his entry, 11Roller- crete to the reinforcement The accepted method
Coaster11, was submitted because it uses concrete to date has been to use a sponge or towel soaked
in a way that is intrinsic to the properties of in a suitable ionic solution to provide a conduc-
reinforced concrete. The sculpture is part of a tive path between the surface of the concrete and
private collection at Killiney, Co Dublin, and is the external electrode. Unfortunately, this wets
described as 11 a wave-like creation 11 by those who the concrete thereby reducing the resistivity and
have seen it. affecting the test results.
The new system overcomes this problem by
using a conductive foam-faced electrode.
Taking Measures to Stop Steel Corrosion Another problem overcome by the ROCC
system is estimating the area of polarized rebar.
Corrosion & Protection Centre Industrial Calculating the corrosion rate requires precise
Services (CAPCIS) is launching a Rate of Con- measurement of the area as any error leads to a
crete Corrosion (ROCC) detection system devel- similar inaccuracy in the rate.
oped from research carried out at the University Charge leakage along the bar makes esti-
of Manchester Institute of Science & Technology mating the area of polarized steel difficult and, in
(UMIST). the past, a limiting ring has been used to control
ROCC as its name suggests, enables engi- the spread of charge. Research by UMIST and
neers to ascertain the rate of corrosion in rein- CAPCIS showed that using a larger electrode
forcement at the time of measurement It uses a negates the effects of this leakage.
surface-mounted probe to measure currents that The trials with the ROCC method showed it
result when a small over-potential is applied to a to be much more sensitive than potential map-
rebar. ping.
Until now, assessment of the condition of To make the corrosion rate date truly useful
reinforced concrete structures has been based on it was necessary to predict when corrosion in
visual inspections, coring and isopotential map- concrete would cause cracking. CAPCIS has
ping. Co-ordinator of CAPCIS' Civils and Con- developed a test using cores taken on site that
struction Division Dr. Gareth John believes that indicate how much deterioration of rebar can be
these methods have their merits but that the tolerated within the concrete. But accelerated
ROCC approach allows a faster and more precise corrosion testing is not particularly accurate and
definition of problems. can also be slow, taking several months to com-
The ROCC system relies on the Linear plete.
436 Journal of Ferrocement: Vol. 20, No. 4, October 1990
with the concomiLant disruption of public serv- World of Concrete, 17th Anniversary
ices, interruption of businesses, and damage to
inventories, contents, and equipment, have made July 1990 marks the 17th anniversary of
this one of the major natural disasters in U.S. World of concrete, the largest annual interna-
history. tional construction industry exposition in the
One of the main lessons of the Loma Prieta United States. The exposition is scheduled for
earthquake is that effort must redouble to mit.i- January 28 through February 1, 1991; and the Las
gate the haz.ards posed by existing seismically Vegas Convention Center, Las Vegas, Nevada
deficient structures. While considerable research USA will host the event.
remains to be done to develop reliable retrofitt.ing The 1991 show will, afford international
procedures, the performance of previously visitors an opportunity to gather and conduct
retrofitted buildings during this earthquake can business in the World of Concrete "International
provide in sight into theeflicacy of variousretrof- Business Center." This gathering point offers a
ining techniques. central location for delegates from all over the
An NSF supported study is currently being world to register for the show, arrange for semi-
supervised by Prof. Stephen Mahin in which nars, familiarize themselves with products and
existing retrofitted buildings are being surveyed equipment being offered by exhibitors or to
and analyzed. More than 500 retrofitted unrein- simply relax.
forced masonry buildings have been inspected For more information on the exposition, or
since the earthquake. This survey indicates that for a brochure listing each seminar plus an in-
most of the retrofitted buildings in the affected depth description of the exposition, write: World
area have only been partialI y upgraded and often of Concrete Registrar, 426 South Westgate ,
only on an ad hoc basic. More than 70 unrein- Addison, IL 60101, USA; or FAX at 708.
forced masonry buildings have been identified 543.3112. Telex "754256 WOC VD".
where a more comprehansive approach to retrof-
itting has been taken. While most of these per-
Morgen Improves Articulation on 32-Meter
formed very well during the earthquake, 16 ex-
Reach Boom
hibited significant localized damage. One of
these damaged buildings is currently being stud-
ied in detail to reconcile observed damage with Morgen has increased the articulation of the
analytical predictions, todetennine what retrofits 32-meter reach boom available on Morgen
would be required by modem guidelines, and to 115SV and 140SV truck pumps. Morgen engi-
assess the potential behavior of these various neers have increased the articulation of the 3rd
retrofits during an even larger seismic event. stage by 45 degrees, from 180 degrees to 225
A related study is also under way regarding degrees.
the performance of retrofitted reinforced con- Improved articulation means increased ver-
crete buildings. Difficulties have been encoun- satility for placing concrete in harder lO reach
tered in this and other studies in gaining access to areas. With the new 225 degree joint, the boom
many damaged buildings due to owner sensitiv- is able to reach farther in under obstructions and
ity or pending legal proceedings. inside the framing of buildings for floor pours.
For more information contact: And, unlike comparable roll and fold booms,
there is no sacrifice in horizontal reach.
Professor Stephen Mahin
EERC. University of California The 32-meter and 28 meter Morgen booms
Berkeley, California 94720 now have state-of-the-art IO micron absolute in-
U.S.A . line pressure filters in the boom elevation and
438 Journal of Ferroce~nt: Vol. 20, No. 4, October 1990
Ferrocement has been identified to be appropriate for repair and strengthening of structures.
IFIC aims to provide this opportunity for ferrocement to be proven effective in this application through
the Journal of Ferrocement Special Issue on Ferrocement for Strengthening and Rehabilitation
of Structures. Papers are invited on research, developments and construction procedure for this
special ferrocement application. Intending authors are requested to submit two copies of abstracts in
English of not more than 500 words. A preliminary acceptance will be made on the basis of the abstract
and the final acceptance will be based on the full-length manuscript.
DEADLINES
Submission of title
and abstracts 1 October 1990
Notification of
preliminary acceptance 15 November 1990
Submission of
completed manuscript 1 February 1991
Notification of
final acceptance 1March1991
IIJFIICC
CC(Q)JN§UJILTAJNT§
IFIC consultants are individuals who are willing to entertain referral letters from IFIC on their field
of expertise.
Mr. Nagesh Govind Joshi Mr. N.V. Raman Mr. H.V. Venkata Krishna
NS Adinath Structural Engineering Research Kamataka Regional Engineering
Antop Hill, Wadala Centre College
Bombay 400 037 CSIR Campus Surathkal (D.K.) Srinivasnagar
India TITI, Tharamani P.O. Kamataka 574 157
Madras 600 113 India
Dr. U.C. Kalita
India
Applied Civil Engineering
Division INDONESIA
Regional Research Laboratory Mr. Kanechamkandy
Council of Scientific and Ravindran Mr. Anshori Djausal
Industrial Research Fishing Technology Division Civil Engineering Department
Jorhat 785 006 (Asam) Central Institute of Fisheries Universitas Lampung
India Technology Lampung
Cochin 682 029 Indonesia
Dr. Surendra Kumar Kaushik India
Civil Engineering Department
Dr. Nilyardi Kahar
University of Roorkee Mr. K.K. Singh
Roorkee 247 667 Lembaga Fisika Nasional-UPI
Civil Engineering Department
India JI. Cisitu-Kompleks LIPI
University of Roorkee
Bandung
Roorkee 247 667
Mr. Ramesh Ranchhodlal Indonesia
India
Kotdawala
L.D. College of Engineering Mr. A. Subramanian Iyer Mr. Ron Van Kerkvoorden
Ahmedabad 380 015 C-15 Yugdharma Complex Rural Water Supply Project
India 27 Central Bazar Road West Java Indonesia
Nagpur-10 JI. Banda 25
Dr. A.G. Madhava Rao India Bandung
Structural Engineering Resarch Indonesia
Centre Dr. B.V. Subrahmanyam
CSIR Campus Dr BYS Consultants Mr. Aji Hari Siswoyo
TITI, Tharamani P.O. 76, 3rd Cross Street PT. WAS ECO TIRTA
Madras 600 113 Raghava Reddi Colony Consultants for Water Supply,
India Madras 600 095 Sanitation and the Environment
India JI. Aditiawarman 28
Dr. S.C. Natesan P.O. Box 116/KBT
Department of Civil Engineering Mr. G.V. Surya Kumar Kebayoran Baru, Jakarta
P.S.G. College of Technology Indonesia
Structural Engineering Research
Coimbatore 4641004 Centre
India Mr. David James Wells
CSIR Campus
P.O. Box410
TITI, Tharamani P.O.
Mr. N.P. Rajamane Jayapura, Irian Jaya
Madras 600 113
Structural Engineering Research Indonesia
India
Centre
CSIR Campus Mr. Winarto
Mr. H.K. Nanjunda Swamy P.O. Box 19 Bulaksumur
TITI, Tharamani P.O.
Madras 600 113 287, Kanapura Road Yogyakarta
India 7th Block, Jayanagar Indonesia
Bangalore 560 082
Dr. S. Rajasekaran India ISRAEL
Department of Civil Engineering
Mr. S.P. Upasani Dr. Fiodor (Efraim) Bljuger
P.S.G. College of Technology
Coimbatore-4 R-11, N.D.S.E. Part-II Building Research Institute
Tamil Nadu 641 004 New Delhi 110 049 Technion City
India India Haifa32000
Israel
JourNJJ of Ferrocemenl: Vol. 20, No. 4, October 1990 445
Mr. Jeremy Martin Morrison Prof. Antoine E. Naaman Dr. Gajanan M. Sabnis
Turner Department of Civil Engineering 13721 Town Line Rd.
Lamas Manor The University of Michigan 304 Silver Spring, MD 20906
Norwich NRlO 5JQ 2340 G.G. Brown U.S.A.
U.K. Ann Arbor, MI 48109
U.S.A. Mr. Stevie Smith
5100 Channel Ave.
Prof. Charles Bryan Wilby Mr. Louis Pevarnik Jr. Richmond, CA 94804
Schools of Civil and Structural P.O. Box 683 U.S.A.
Engineering Latrobe, PA 15650
Prof.Dr. Michael A. Taylor
University of Bradford U.S.A.
Civil Engineering Department
Bradford, Yorkshire BD7 lDP
University of California at Davis
U.K. Dr. S.P. Prawel Jr. Davis, CA 95616
Department of Civil Engineering U.S.A.
U.S.A. State University of New York at
Buffalo Mr. Lois L., Jr. Watson
231 Ketter Hall 1708 Ferndale Circle
Dr. Perumalsamy N. Balaguru Buffalo, NY 14260 West Sacramento
Department of Civil Engineering U.S.A. CA 95691
Rutgers The State University of
U.S.A.
New Jersy Mr. Steven Iddings
Box 909 5825 Horsehoe Bend Road
Piscataway, NJ 08854 Prof. Robert Brady Williamson
Ludlow Falls, OH 45339
U.S.A. U.S.A. Department of Civil Engineering
University of California
Mr. Russell J. Bartell 773 Davis Hall
Mr. Guruvayur Subramaniam Berkeley, CA 94720
615 SW St. Lusie St. Ramaswamy U.S.A.
Stuart, FL 33497
Department of Civil Engineering
U.S.A. Dr. Ronald F. Zollo
University of Arizona
Tuczon, AZ 85721 Department of Civil Engineering
Dr. Gary Lee Bowen U.S.A. University of Miami
P.O. Box 2311 Coral Gables, FL 33124
Sitka, AK 99835 Dr. Andrei Reinhorn U.S.A.
U.S.A. Department of Civil Engineering
State University of New York at
Mr. John R. Gusler Buffalo VANUATU, SOUTH PACIFIC
6893 S Sectionline Road 231 Ketter Hall
Delaware, OH 43015 Buffalo, NY 14260
U.S.A. U.S.A. Mr. Gerald James Neuburger
P.O. Box 240
Dr. George C. Hoff Mr. Eldred Hiter Robinson III Santo
Mobil Research and Development 6055 Flamingo Dr. Vanuatu, Southwest Pacific
Corp. s14, Roanoke
P.O. Box 819047 Virginia
Dallas, Texas 75381 U.S.A.
U.S.A.
Dr. James Romualdi
Mr. Martin E. Iorns
Department of Civil Engineering
Ferrocement Laminates Carnegie-Mellon University
1512 Lakewood Drive
U.S.A.
W. Sacramento, CA 95691
U.S.A.
450 Journal of Ferrocement: Vol. 20, No. 4, October 1990
Bangladesh University of
University of Roorkee Instituto Mexicano del Cemento
Engineering and Technology
Department of Civil y del Concrete
Civil Engineering Department
Engineering A.C. (IMCYC)
Dhaka 1000
Roorkee 247667 Insurgentes Sur 1846
Bangladesh India 01030 Mexico, D.F.
Coordinators: Coordinators: Mexico
Dr. A.M. Taufiqul Anwar Dr. DN. Trikha
Dr. S.K. Kaushik Coordinator:
Ing. Julio Ernesto Lira
CHINA INDONESIA
Institut Teknologi Bandung
Dalian University of Center for Research on
Technology PAKISTAN
Technology
Structural Laboratory Institute for Research NED University of Engineer-
Dalian, 116024 P.O. Box 276
Bandung
ing and Technology
China
Coordinator: Indonesia University Road
Professor Zhao Guo/an Coordinating Committee: Karachi - 75270
Dr. W. Merati Pakistan
Mr. Ansori Djausal Coordinator:
Mr. Umar Handajo
CUBA Dr. Sahibzada Farooq Ahmed
Ms. Anna R. Gani
Dr. Puti Tamin
Technical Information PHILIPPINES
Center MALAYSIA
Empresa de Proyectos de Obras University of the Philippines
para el Transporte College of Engineering
Oficios 172, La Habana 1 Universiti PertanianMalaysia Diliman, Quezon City 1101
Cuba Faculty of Engineering Philippines
Coordinator: Serdang, Selangor Coordinator:
Mr. Fidel Delgado Malaysia Professor Jose Ma. de Castro
Coordinator:
Prof. A. A. Abang Ali
Journal of Ferrocement: Vol. 20, No. 4, October 1990 451
ARGENTINA BRAZIL
sity of lllinois at Chicago Circle, U.S.A. respec- nois at Chicago and at Mas-
tively. His main research interests are cost opti- sach useus Institute of
mum design, time dependent and fatigue behav- Technology. He has more
ior of ferrocement, reinforced and prestressed than 100 publications deal-
concrete structures and structural mechanics. ing with properties of con-
He has over 50 publications in the area of his re- crete; behavior of rein-
search interest Dr. Balaguru is a member of the forced concrete members,
Board of Direction of the New Jersey American and fiber reinforced con-
Concrete Institute, and member of the American . crete. He is chairman of
Concrete Institute (ACI) Technical Committee ACI Committee on Fatigue of Concrete Struc-
215 on Fatigue of Concrete. He is the chairman tures, and RILEM committee on Ferrocement;
of the ACI Technical Committee 549 on Ferro- also past chairman of the ASCE-EMD commit-
cement. tee on Properties of Materials. He is on the
editorial board of four international journals and
S.P. SHAH a fellow of the American Concrete Institute. He
was the 1980 RU.EM Gold Medal awardee and
Dr. Shah is professor of civil engineering was a guest professor at Delft Institute of Tech-
and director of the Center for Concrete and Geo- nology. His current research interests include:
materials at Northwestern University and edito- constitutive relations of concrete, application of
rial board member of the Journal of Ferroce- nonlinear fracture mechanics to rocks and con-
menl. He received his Ph.D. from Cornell Uni- crete; impact loading, fiber reinforced concrete
versity. He has taught at the University of Illi- and bond between steel and concrete.
462 Journal ofFerrocem£nt: Vol. 20, No. 4, October 1990
REFERENCE: Raj, V. 1990. Farge Span Bamboo Fcrroccmcnt Elements for Flooring and Roofing
Purposes. Journal of Fcrroccmcnt 20 (4): 367-374.
IINTJEIBN.&TII(Q)N.&IL
™I JE JE 1rII N CG§
January 7-12, 1991: Constitutive Laws for En- 1991: 2nd Regional Conference on Computer
gineering Materials, 3rd International Con- Applications in Civil Engineering - RCCACE
ference, Tucson, U.S.A. Contact: Office of '91, Johor Bahru, Malaysia. Contact: Organiz-
Engineering and Professional Development, ing Secretary RCCACE '91, Faculty of Civil
University of Arizona, Tucson, AZ 85721, Engineering, Universiti Teknologi Malaysia,
U.S.A. Karung Berkunci 791, 80990 Johor Bahm, Ma-
laysia.
January 28-February 1, 1991: Aberdeen's
World of Concrete'91 , Las Vegas, U.S.A : March 14-15, 1991: Asia-Pacific Conference
Contact: World of Concrete Centre, 426 South on Masonry, Singapore. Contact: Engr. John
Wes(8ate, Addison, IL 60101 U.S.A. S.Y. TanCI-PremierPte.Ltd., 1500rchardRoad
#07-14, Orchard Plaza, Singapore 0923. Tel:
January 18-19,1991: International Confer- 7332922; Fax: 2353530; Telex: RS 33205.
ence on Durability of Reinforced and
Prestressed Concr_ete Structures, Jodhpur, April 4-5, 1991: Third International Confer-
India. Contact: Prof. S. Divakaran, Conference ence on Structural Failure-ICSF 91, Sin-
Director, Department of Structural Engineering, gapore. Contact: Dr. K.H. Tan, Department of
M.B.M. Engineering College, Jodhpur-342 001, Civil Engineeering, National University of Sin-
India. gapore, 10 KentRidge Crescent, Singapore051 l.
Tel.: 7722260; Fax: (65) 7791635; Telex:
UNISPO RS33943; Telegram: UNIVSPORE.
February 8-10, 1991: International Confer-
ence on Bridges and Flyovers, Hyderabad,
April 7-11, 1991: Development and the Envi-
India. Contact: Bureau of Industrial and Re- ronment, Tasmania, Australia. Contact: The
search & Development, Jawaharlal Nehru Tech- Conference Manager, the Institution of Engi-
nological University, Mahaveer Marg, Hydera- neers, Australia, 11 National Circuit, Barton Act,
bad-500 028, India. Australia 2600. Tel.: (06)2706549; Fax: (06)
2706530; Telex: AA62758.
February 10-15, 1991: International Sympo-
April 8-11, 1991: Conference on Deformation,
sium on Polymer Materials Preparation Yield and Fracture of Polymers, Cambridge,
Characterization and Properties, Melbourne, England. Contact: Plastics and Rubber Institute,
Australia. Contact: RACI Polymer Division, Conference Department, 11 Hobart Place, Lon-
P.O. Box 224, Belmont Victoria, Australia 3216. don, England SWlW OHL.
Journal of Ferrocement: Vol. 20, No. 4, October 1990 465
April 14-18, 1991: Sixth International Sym- August 4-9, 1991: International Conference
posium: Tunnelling '91, London, U.K. Con- on Durability of Concrete, Montreal, Canada.
tact: The Conference Office, Institution of Min- Contact: Mr. H.S. Wilson, P.O. Box 3065, Sta.
ing and Metallurgy, 44 Portland Place, London, C., Ottawa, Canada KIY 413.
U.K. WIN 4BR.
August 20-22, 1991: Computational Struc-
April 21-25, 1991: International Conference tures Technology, Edinburgh, U.K. Contact:
on Computational Engineering Science, Pa- Edinburgh Conference Centre Limited (Forth
tras, Greece. Contact: Prof. S.N. Atluri, Compu- Rail bridge Centenary Conference), Heriot-Watt
tational Mechanics Center, Georgia Tech., At- University, Riccarton, Edinburgh, U.K. EH14
lanta, GA 30332-0356, U.S.A. 4AS, Tel.: 031-4495111 Ext.3117; Fax: 031-
4513199.
Apri/23-26, 1991 :The Third East Asia-Pacific
Conference on Structural Engineering and August 25-30, 1991: Composite Polymeric
Construction (EASEC - 3), Shanghai, China. Material, New York, U.S.A. Contact: Mr. R.S.
Contact:EASEC - 3 Secretariat, Mr. H.F. Xiang/ Turner, ACS Division of Polymeric Materials,
Mr. D.H. Jiang, Tong.ii University, 1239 Siping Building 82, Eastman Kodak Co., Rochester, NJ
Road, Shanghai 200092, China. Tel.:5455080- 14650, U.S.A.
3420; Cable:3658; Fax:0086-02 l-5458965;
Telex:33488 TJIDC CN. September 3-6, 1991: Diagnosis of Concrete
Structures, Czechoslovakia. Contact: Doc. Inc.
June 3-7, 1991: 11th FIP Congress, Ham- Tibor JAVOR, Dr.Sc. VUIS Lamacska 8, 81714
burg, West Germany. Contact: FIP Office, Bratislava, Czechoslovakia.
The Institution of Structural Engineers, 11 Upper
Belgrave Street, GB-London, United Kingdom October 22-25, 1991: International Sympo-
SWlX 8BH. sium on Modern Application of Prestressed
Concrete, Beijing, China. Contact: Professor
June 10-13, 1991: 5th Annual Technical Con- Liu Yongyi, China Academy of Building
ference on Composite Materials, Michigan, Research (CABR), P.O. Box 752, Beijing
U.S.A. Contact: Dr. L.T. Drzal, American Soci- 100013, China.
ety for Composites, BlOO Research Comples,
Michigan State University, East Lansing, MI
48824-1326, U.S.A. December 4-6, 1991: ACI International Con-
ference on Evaluation andRehabilitation of
June 27-28, 1991: New Dimensions in Bridges Concrete Structures and Innovations in De-
and Flyovers, Singapore.Contact: Engr. John sign, HongKong. Contact: Mr. William R.
S.Y. TanCI-PremierPte.Ltd., 1500rchardRoad Tolley, American Concrete Institute, 22400 W.
#07-14, Orchard Plaza, Singapore 0923. Tel: Seven Mile Road, Detroit, MI 48219-1849,
7332922; Fax: 2353530; Telex: RS 33205. U.S.A.; Fax:(313)532-0655.
July 29-31, 1991: Fourth International Con- May 3-8, 1992: International Conference on
ference on Computing in Civil/Building Engi- Fly Ash, Silica Fume, Slag and Natural Pozzo-
neering, Tokyo, Japan. Contact: Mr. Junichi lans in Concrete, Istanbul, Turkey. Contact:
Yagi, Managing Director, Office of Japan, Soci- Mr. H.S. Wilson, P.O. Box 3065, Station C.
ety of Civil Engineers, Yotsuya 1-0, Shinjukuku, Ottawa, Canada Kl Y 413
Tokyo, Japan.
466 JourNJI of Ferrocemenl: Vol. 20, No. 4, October 1990
CONTENT LIST
Volume 20 contains four issues and this partial list of contents includes all technical articles
including papers on research and development, applications and techniques, tips for amateur builders
and news and notes published in the Journal of Ferrocement during 1990.
DISCUSSION
NEW &NOTES 58
Fourth International Symposium on Ferrocement to be Held in Cuba 59
International Conference for Editors 59
Ferro Systems Europe 60
Substituting Cement With Steel Slag 61
Experts Examine Impact of New Technologies on Third World 61
Ferrocement Tank Manual 62
Ferrocement Caution and Sign Boards 62
Ferrocement Water Storage Tanks Installed at High Altitude Locations 63
National Seminar on Special Concretes 63
Precast Ferrocement Bridge Deck Slabs 64
Tough Metallic Fibers 65
Ferrocement Water Tanks 65
Journal of Ferrocemenl: Vol. 20, No. 4, October 1990 467
DISCUSSION
SPECIAL FOCUS
AUTHOR INDEX
Agustin, R. Bowen, G.L.
Technological DevelopmenJ of Upgrading a FerrocemenJ Boat Stern
Low Cost Materials in ASEAN Tube de Hanai, J.B. 39
CounJries 265 FerrocemenJ Precast Retaining Walls. 31
AI-Rifaie, W.N. Fwa, T.F.
Effect ofArrangemenJ and OrienJation FerrocemenJ Overlay for Concrete PavemenJ
of Hexagonal Mesh on the Behaviour Resurfacing 23
of Two-Way Slabs 219 Garrote, B.M.
AI-Sulaimani, G.J. Construction and Use of FerrocemenJ Paving
Structural Behavior of FerrocemenJ Blocks 125
Load Bearing Wall Panels 1 Giugan. G.
Baetens, T. Fabrication and Specifications of
Fabrication and Specifications of FerrocemenJ Doors
FerrocemenJ Doors. Hawlader, M.N.A.
Balaguru, P. Thermal Behaviour of FerrocemenJ 231
Ductility of FerrocemenJ Beams 349 Lee, S.L.
Basunbul, I.A. Rainwater Storage Using FerrocemenJ
Structural Behavior of FerrocemenJ Tanks in Developing CounJries 377
Load Bearing Wall Panels 1
472 JourNJ/ of Ferrocement: Vol. 20, No. 4, October 1990
SUBJECT INDEX
Walls Ferrocement 1, 11, 23, 31, 39, 45, 62, 63,
Bearing~ 125, 133, 143, 149, 159, 181, 219,231,
Load - Panels 1 241,257,269,349,357,367,377,385
Retaining walls 31
Bearing - System 141 Irrigation 11
Journal of Ferrocement: Vol. 20, No. 4, October 1990 473
TITLE INDEX
'(~(~~ !
I (!}'LJ[S I
This publication discusses every aspect of Edited byR.P. Pama, Seng-Lip Lee andNoelD.
ferrocement technology: historical background, Vietmeyer
constituent materials, construction procedures,
mechanical properties and potential applications. This report is the product of the workshop
The flexicover edition includes over 75 literature "Introduction of Technologies in Asia -
references on the subject. 149 pp., 74 illus. Ferrocement, A Case Study", jointly sponsored
by the Asian Institute of Technology (Ain and
Surface mail Air mail the U.S. National Academy of Sciences (NAS).
Subscribers US$12.00 US$14.00 Thirteen case studies on the 'State-of-the-Art' of
Non-subscribers US$15.00 US$17.00 ferrocement technology and applications in nine
countries in Asia and Australia are presented.
106 pp., 59 illus.
This directory is an indispensable source for This is a compilation of the lecture notes of
decision making to select firms/experts for the Short Course on Design and Construction of
ferrocement related design, construction and Ferrocement Structures held at the Asian
engineering services. Institute of Technology, Bangkok, Thailand,
226 firms and experts present their 8-12 January 1985. This publication contains
capabilities and experience. In addition, they are every aspect of ferrocement from its historical
indexed by types of services performed and by background and constituent materials to the
geographic location of their offices. construction procedures. An important feature of
the lecture notes is the design criteria for
Surface mail Air mail ferrocement including examples of analysis
For Experts and Firms US$ 5.00 US$ 7.00 problems based from the "ACI Design Guide for
listed in the directory Ferrocement."
List price US$15.00 US$17.00
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JOURNAL OF FERROCEMENT
Volume 20, Number 4, October 1990
CONTENTS
ABOUTIFIC
11111fi I llffil l IH II~
202799 ii
EDITORIAL iii
SPECIAL FOCUS
Research on Ferrocement- Global Perspectives 385
R.P.Pama
Bibliographic List 411
Fast Lookup 421
News and Notes 423
Call for Papers 439
IFIC Consultants 441
Ferrocement Information Network 450
IFIC Reference Centers 452
Authors' Profile 459
Abstracts 462
International Meetings 464
Content List (Vol. 20) 466
Index (Vol.20) 471
IFIC Publications 475
Advertising Rates and Fees for IFIC Services 482
Advertisement 483
Discussion of the technical material published in this issue is open until 1 January 1991 for publication in the Journal.
The Editors and the Publishers are not responsible for any statement made or any opinion expressed by the authors in the
Journal. No pan of this publication may be reproduced in any form without written permission from the publisher. All
correspondences related to manuscript submission, discussions, permission to reprint, advertising, subscriptions or change of
address should be sent to: The Editor, Journal of Ferrocement, IFIC/AIT, G.P.O. Box 2754, Bangkok 10501, Thailand.
The International Ferrocement Information Center (IFIC) was founded in October 1976 at
the Asian Institute of Technology under the joint sponsorship of the Institute' s Division of Structural
Engineering and Construction and the Library and Regional Documentation Center. IFIC was
established as a result of the recommendations made in 1972 by the U.S. National Academy of
Sciences' Advisory Committee on Technological Innovation (ACTI). IFIC receives financial support
from the Canadian International Development Agency (CIDA) and the International
Development Research Center (IDRC) of Canada.
Basically, IFIC serves as a clearing house for information on ferrocement and related materials.
In cooperation with national societies, universities, libraries, information centers, government
agencies, research organizations, engineering and consulting firms all over the world, IFIC attempts
to collect information on all forms of ferrocement applications either published or unpublished. This
information is identified and sorted before it is repackaged and disseminated as widely as possible
through IFIC's publications, reference and reprographic services and technology transfer
activities. All information collected by IFIC are entered into a computerized data base using ISIS
system. These information are available on request. In addition, IFIC offers referral services.
A quarterly publication, the Journal of Ferrocement, is the main disseminating tool of IFIC.
IFIC has also published the monograph Ferrocement, Do It Yourself Booklets, Slide Presentation
Series, State-of-the-Art Reviews, Ferrocement Abstracts, bibliographies and reports. FOCUS, the
information brochure ofIFI C, is published in 19 languages as part of IFIC' s attempt to reach out
to the rural areas of the developing countries. IFIC is compiling a directory of consultants and
ferrocement experts. The first volume, International Directory of Ferrocement Organizations and
Experts 1982-1984, is now being updated.
To transfer ferrocement technology to the rural areas of developing countries, IFIC organizes
training programs, seminars, study-tours, conferences and symposia. For these activities, IFIC acts
as an initiator; identifying needs, soliciting funding, identifying experts, and bringing people together.
So far, IFIC has successfully undertaken training programs for Indonesia and Malaysia; a regional
symposium and training course in India; a seminar to introduce ferrocement in Malaysia; another
seminar to introduce ferrocement to Africans; study-tour in Thailand and Indonesia for African
officials; the Second International Symposium on Ferrocement and a Short Course on Design and
Construction of Ferrocement Structures, and the Ferrocement Corrosion: An International
Correspondence Symposium. IFIC has successfully established the Ferrocement Information
Network (FIN), the IFIC Reference Centers network and the IFIC Consultants network. IFIC has
promoted the introduction of ferrocement technology in the engineering and architecture curricula of
144 universities in 50 countries. Currently, IFIC is involved to strengthen the outreach programs of
the nodes of FIN.
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JOURNAL OF FERROCEMENT
PRINTED 8Y THAI WATAHA PANICll PRUS 00 •• I.TD •• 891 R.UIA I ROAD 0 llANQKOK. MR. THIRA T. SUWAN, PRINTER, B.E. 2533