Construction and Building Materials 34 (2012) 470–475

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Construction and Building Materials

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Reuse of cotton and recycle paper mill waste as building material

D. Rajput a, S.S. Bhagade a, S.P. Raut b, R.V. Ralegaonkar b, Sachin A. Mandavgane c,⇑
a
Department of Chemical Engineering, Anuradha Engineering College, Chikhli, Maharashtra, India
b
Department of Civil Engineering, VNIT, Nagpur, Maharashtra, India
c
Department of Chemical Engineering, VNIT, Nagpur, Maharashtra, India

a r t i c l e i n f o a b s t r a c t

Article history: Cotton waste results from the mechanical processing of raw cotton in yarn mills. Recycle Paper Mills con-
Received 4 December 2011 stitute 30% of total pulp and paper mill segment in India. With 85% average efficiency of Recycle Paper
Received in revised form 17 February 2012 Mills, 15% waste is produced annually. Recycle Paper Mills waste and cotton waste has been utilized
Accepted 25 February 2012
to make Waste Crete Bricks. It helps in solid waste management, generate additional revenue and help
Available online 9 April 2012
in earning carbon credits. Waste Crete Bricks with varying content of cotton waste (1–5 wt.%), Recycle
Paper Mills waste (89–85 wt.%) and fixed content of Portland cement (10 wt.%) have been prepared
Keywords:
and tested as per IS 3495 (Part 1–3): 1992 standards. The characteristics of raw materials, which is the
Cotton waste
Recycle Paper Mills waste
base material for Waste Crete Bricks, have been determined using XRF, TG–DTA, and SEM. TG–DTA indi-
Bricks cate that bricks is thermally stable up to a temperature of 280 °C while SEM monographs show its porous
Thermal conductivity and fibrous nature. The bricks meet of IS 3495 (Part 1–3): 1992.
Ó 2012 Elsevier Ltd. All rights reserved.

1. Introduction composting, anaerobic treatment, recycling and others [2]. The

need to conserve traditional building materials (such as clay)
Accumulation of unmanaged wastes, especially in developing which are fast depleting, have obliged engineers to look for alter-
countries, is the cause of environmental concerns. Such concerns native materials Recycling of such wastes by incorporating them
can be partially addressed by recycling of such wastes. Converting into building materials is a practical solution to the pollution
such wastes into building materials appears to be a viable solution. problem.
It not only helps in mitigating the pollution problem but also leads These agro residues are reinforced with cement composites in
to reduced cost of buildings without compromising on structural varying proportion of vegetable fibers. Experimental investigations
strength. reveal that adding ratified vegetable fibers reduces composites ther-
Brick is one of the basic materials for construction industry. mal conductivity, increases mechanical strength and yields lighter
Infrastructure such as bridges, canals, roads as also buildings for composites. Moreover, the more the fibers, the lighter the specimen;
housing and industry need large amounts of construction materi- lower its thermal conductivity and lower its specific heat [3].
als. Due to the large demand of building materials – especially in Recycle Paper Mills use recycled waste paper along with virgin
the last decade owing to the increasing population – there is a mis- pulp to produce mainly packing paper. The pulp is made into paper
match between demand and supply of these materials. Hence to by paper-making machines. Long length fibers go into the paper
meet the continuously increasing demand, researchers are sheet on the machine while short length fibers pass through the
attempting to design and develop sustainable substitutes for the machine belt and are separated at the end filter from the waste
construction materials. The imperative need to use environmental water. This constitutes the Recycle Paper Mills waste (PW). The
friendly, low cost and lightweight construction materials in build- PW is otherwise of no use and is usually land filled. PW is reported
ing industry has engaged the attention of investigators. The task is to be used in making light weight bricks [4].
to achieve this while meeting the required standards. Similarly, the residual or secondary cotton wastes in the yarn
Brick is one of the most flexible masonry units. Attempts have production have little value and are difficult to dispose off. Because
been made to incorporate waste in the production of bricks [1]. of the differences in the manufacturing facilities, it is not easy to
The by-products and residues from pulp and paper industry are determine the quantity of cotton waste (CW) so generated. It is
disposed off using several approaches including land filling, incin- estimated that approximately 7% of cotton ends up as waste. Most
eration, use in cement plant and brickworks, agricultural use and of CW is landfilled or open-dumped into uncontrolled waste pits
and open areas. Disposal of this product waste is a major problem
⇑ Corresponding author. Tel.: +91 712 2801563; fax: +91 712 2223969. for the many small cotton yarn businesses. Literature reports use of
E-mail address: sam@che.vnit.ac.in (S.A. Mandavgane). CW as brick material [5].

0950-0618/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
doi:10.1016/j.conbuildmat.2012.02.035
 D. Rajput et al. / Construction and Building Materials 34 (2012) 470–475 471

The major pollution problems being faced by small-scale Recy- Table 1

cled Paper Mills and Yarn Mills is due to the huge amount of solid Details of compositions.

sludge waste generation and the limited treatment facilities. The Sr No. Sample Cement (g) Water (g) CW (g) PW (g) Total (g)
use of PW and CW (PCW) as brick material is a sustainable solution 1 A 90 2305 45 760 3200
to solid waste management. The bricks manufactured using these 2 B 90 2300 30 780 3200
wastes are lightweight due to the presence of tiny air pockets 3 C 90 2301 9 800 3200
inside. These pockets also result in better thermal insulation and Sample A: 85% PW + 10% Cement + 5% CW.
shock absorption properties. Sample B: 87% PW + 10% Cement + 3% CW.
The present paper focuses on development of bricks using Sample C: 89% PW + 10% Cement + 1% CW.
PCW–cement combination. Low cost hand operated mixing and
steel molds (Fig. 2). Nearly 3200 gm of 70% mix is added to the mold. The top of the
molding machinery has been designed and fabricated for the pro-
mold had a uniform perforation consisting of 3 mm holes to facilitate the release of
duction of the bricks. The properties of bricks produced by varying moisture. The mix was pressed (P1) in the mold until 25 ± 4% of its initial moisture
the content of the components have been determined. The tests was removed. The bricks were taken out and kept for sun and air drying until its
recommended by Bureau of Indian Standards have been carried moisture was reduced by an additional 15 ± 3%. The semi-dried bricks were further
out on the bricks made. pressed (P2) till its moisture content was reduced by 10 ± 2% and then kept for final
sun and air drying. The final dimensions of the bricks were measured to be 230 
105  80 mm. As PCW is fibrous in nature, it holds moisture inside and does not re-
2. Materials and methods lease it easily. It was observed that if bricks were made in a single stage, upon dry-
ing the brick surface became irregular and uneven. This was because, when the
Recycle Paper Mill Waste (PW) has been obtained from M/s Madhydesh Paper bricks were made under high pressure in a single stage, the pressure distribution
Mill, Nagpur, India. The mill mainly works in recycling the newspaper waste. The inside the core of the brick and on the surface was same and relatively high. As
cotton waste (CW) has been obtained from the PM Yarn Mills, Chikhli, India. The the wet bricks were sun dried, moisture from the surfaces evaporates, creating a
PW is combined with CW in different proportions. The composite is then mixed concentration gradient of moisture between core and the surface. On the other
with Portland cement (43-grade, confirming to Bureau of Indian Standards (BIS), hand, while driving moisture at high pressure, the moisture travels from the core
IS: 12269) made by Associated Cement Companies, Chandrapur, India. to the surface, creating another moisture gradient between the core and the surface.
When the moisture under pressure reaches the surface it deforms the surface and
2.1. Characterization of materials makes it irregular. Hence, in order to preserve the surface smoothness on drying,
the bricks were made in two stage operations. Following this procedure, 60 samples
Energy Dispersive X-ray Fluorescence Spectrometer (XRF, Philips, PW 1840) (A, B and C) each with varying composition of PW, CW and Cement were prepared.
was used for chemical characterization of PW and CW. To determine the thermal Table 2 shows the detailed material balance of each sample composition.
stability of PW, thermo-gravimetric–differential thermal analysis (TG–DTA) was
performed using TG–DTA (Model – Mettler, TA 4000). Scanning electron micro- 3. Test methods
graph photographs have been recorded using JEOL Model No. JXA – 840 A, Japan.

The compressive strength of bricks was determined using

2.2. Mixing and fabrication of bricks
Compression Testing Machine (CTM). Three samples of each com-
A hand-operated hydraulic press (Fig. 1) was used to make bricks of dimensions position were subjected to a compressive strength test, and the
230  105  80 mm. Various batches of mix of PW, CW and cement were prepared. average strengths were recorded. Compressive strength test, water
Sixty (60) samples, each comprising of varying percentage of PW, CW and cement absorption test and efflorescence were performed according to IS
were prepared. Sample set A has 85% PW, 5% CW and 10% of cement by weight,
3495 (Part 1–3): 1992. Physical properties such as specific weight,
sample set B has 87% PW, 3% CW and 10% of cement by weight whereas sample
set C has 89% PW, 1% CW and 10% of cement by weight. All sample compositions voidage and equilibrium moisture content and dimension change
were prepared with uniform consistency (22 ± 1%). The detailed information of on drying were determined following the IS 1077: 1992 guidelines.
the final composition of the mixture is presented in Table 1. Block density and moisture movement for the hollow and solid
In order to homogeneously mix different compositions, PW, CW and cement blocks were measured according to the IS: 2185 (Part 1): 1979.
were mixed in a specially designed and fabricated mixer for 2 min. CW obtained
from the mill was very short fibers. They were mixed with other raw materials in
homogenizer as obtained from the mill. Since PW and CW is fibrous and lumpy 3.1. Determination of thermal conductivity (k-value)
in nature, the blades of the mixer were designed in such a way that it shears the
PCW mass with each rotation. It was observed that PW was uniformly scattered k-Value of sample is measured using Lee’s apparatus as per
within the mixes forming a homogeneous mixture with CW and cement. In order
to obtain a homogeneous mix, water was sprayed intermittently by the air pump
ASTM C 177. Lee’s apparatus consists of water container and two
onto the mixes while the mixer was turning. Once the water was sprayed, an addi- brass discs. Disc of the sample is made and it is sandwiched
tional 5 min of mixing was conducted. Afterward, the fresh mixes were fed into the between two brass discs. Steam is passed through the upper disc.
Temperature is measured using thermometers. Calculation of

Fig. 1. Homogenizer for mixing PCW and cement. Fig. 2. Design of mold for making bricks using PCW–cement mix.
472 D. Rajput et al. / Construction and Building Materials 34 (2012) 470–475

Table 2 where the material gets thermally degraded and gets sintered.
Material balance. Based on the TG curves, it can be concluded that the bricks made
Sample A B C Average (%) from PW can withstand at the minimum of 300 °C. The third mass
Weight (wt) of wet PW, gm 3200 3200 3200 loss beyond 300 °C is due to combustion of solid organic matter
Wt of dry PW, gm 760 780 800 present in PW.
Wt of cement, gm 90 90 90 Differential scanning calorimetry (DSC) (Fig. 3) measures
Wt of cotton waste, gm 45 30 9 Specific Heat Capacity, Heat of Transition, Temperature of Phase
Water, gm 2305 2300 2301
Wt of wet brick after P1, gm 2738 2710 2689
Changes and Melting Points. In the present case DSC thermal anal-
Amount of water removed by 610 619 602 15 ± 3a ysis was carried out to determine the phase change. DSC measures
partial solar drying, gm the rate of heat flow. DSC compares differences between the heat
Wt of wet brick before P2, gm 2128 2091 2087 flow rate of the test sample and known reference materials.
Wt of wet brick after P2, gm 1926 1877 1846
Vertical axis denotes rate of heat liberated per unit mass of PW
Amount of water removed 202 214 241 10 ± 2a
during P2, gm (mW/mg). From TGA and DSC second mass loss coincides with
Wt of dry brick, gm 948 976 983 maximum heat liberated. It confirms that phase change of PW
Amount of water removed by 935 971 946 42 ± 5a takes place at 280 °C and it gets thermally degraded.
partial solar drying, gm SEM monograph (Fig. 4) for PW and (Fig. 5) for PCW clearly
Wt of dry material, gm 896 896 896
indicate the presence of irregular pores and their fibrous nature.
Wt of water in brick, gm 52 80 87 8 ± 2a
Wt of water removed 664 704 752 35 ± 5a The PCW holds the moisture in the pores and the fibrous structure
by pressing, gm of RPMR encapsulates the moisture thereby creating a barrier for
Wt of water removed 1545 1590 1548 57 ± 5a moisture to move towards the surface. Fibers of CW are intern
by evaporation, gm
woven and spread uniformly in the PCW–cement mix that gives
a
Values based on initial water content. better deformability.

4.2. Brick analysis

conductivity has been done by making heat balance. Thermal con-
ductivity has been measured for different compositions at 40 °C.
Three brick samples each from A, B and C compositions were
used for conducting the compressive strength tests. Additional
4. Results and discussion three samples were also used for conducting the specific weight,
voidage, and water absorption tests. The test results shown in
4.1. Characterization of PW and CW Table 4 indicate that the bricks conform to the minimum compres-
sive strength requirements stipulated in IS 1077 (Part 1): 1992.
Elemental analysis (Table 3) shows that pozzolanic silica con- Initial moisture content of PCW is approximately 75%. The final
tent in PW and CW were 60.57% and 35.4% respectively. Pozzolanic moisture content of the brick is approximately 8%. On drying, the
silica participates in pozzolanic reaction to form cementitious space occupied by moisture is occupied by air. Voidage fraction is
material. Elemental Calcium (Ca) content in PW and CW is 15% the ratio of volume occupied by the dry solid (dry PW + CW + cement)
and 28% respectively. Heavy metals copper (Cu), strontium (Sr), to the total volume of the dry brick (length  breadth  height). From
zirconium (Zr) and manganese (Mn) were present in traces (less the results it is observed that with increase in CW proportion the
than 0.1%). Therefore, the possibility of leaching heavy metals is voidage fraction increases. It was also observed that voidage of the
insignificant. brick sample decreases with an increase in PW content.
Thermogravimetric analysis (TGA) of PW was carried out to Voidage fraction impacts water absorption property of brick.
measure the amount and rate of change in the weight of a material For water absorption test, brick is sample is soaked in water for
as a function of temperature or time in a controlled atmosphere, 24 h. Water molecules enters into the bulk of the brick and occu-
Measurements were used primarily to predict thermal stability at pies the void. It is observed that with decrease in voidage fraction
temperatures up to 1000 °C. The results from thermogravimetric from 0.29 to 0.18, the water absorption decreases from 105% to
analyses are usually reported in the form of curves relating the 99%. Thus with decrease in proportion of CW, voidage fraction
mass loss from the sample against temperature. In this form the and % water absorption decreases. Swelling of bricks i.e. dimension
temperature at which certain processes begin and are completed change on water absorption also reduces with decreasing CW
are graphically demonstrated. TGA curve obtained from heating a proportion.
sample of PW from 30 °C to 1000 °C is shown in Fig. 3. The curve It is also observed that even with change in CW there is con-
shows the loss in weight that occurred at different temperatures. stant (8%) volume change on drying. The reason for change in
According to the TG curves shown in Fig. 3, PW samples showed dimensions on drying is removal of almost 60% moisture on drying
the mass loss of 45% between 29 °C and 300 °C. It should be noted (Initial moisture content 77% and final moisture content is 10%).
that this mass loss was observed on the samples which were not Hence when moisture is removed by drying the brick shrinks and
thermally pre-treated. This curve reveals the appearance of three volume of the brick decreases.
distinct mass loss regions. The first loss (7.5%) occurred between The probable reason for decrease of voidage fraction, decrease
30 °C and 280 °C which is premature loss and could be attributed of % water absorption and increase in volume change on water
to the removal of superficial water molecules that may be present absorption with decrease in % CW is that, CW has fibrous and
in the solid pores. The second mass loss occurs beyond 280 °C has very low specific weight.

Table 3
Elemental analysis of PW.

O (%) Ca (%) Si (%) Al (%) Mg (%) S (%) Ti (%) K (%) Fe (%) Na (%) Cu (%) P (%) Cl (%)
PW 15.8 14.9 60.5 2.1 3.6 1.07 0.15 0.16 0.92 0.22 0.05 0.03 0.41
CW 22.0 28.3 35.4 11.2 2.4 – – – 0.56 – – – –
 D. Rajput et al. / Construction and Building Materials 34 (2012) 470–475 473

Fig. 3. TG–DTA of PW.

Fig. 4. SEM monograph of PW sample.

Fig. 5. SEM monograph of CW sample.

Moisture content of dry brick samples of A, B, and C was than PW hence with increase in proportion of CW, specific weight
observed in the range of 5–8%. The plus/minus bracket in Table 4 of PCW–cement brick decreases. Thus with increase in proportion
stands for the maximum/minimum from the results on three sam- of PW, bricks become lighter. Specific weight of burnt clay brick
ples per test per used material. Moisture content of sample A in and fly ash brick is 1.7 and 1.75 gm/cc respectively. Table 5 shows
Table 4 is reported as 8.85 ± 2%, it means that moisture contents comparative study of different brick materials.
of three samples of A varies between 6% and 10%. The higher water The dry compressive strength of brick samples is determined
absorption for bricks with higher CW content is due to the voids. using CTM. All brick samples show excellent compressive strength
Specific weight of PW–cement [4] and CW–cement [5] is 0.65 (21 ± 1 MPa) as compared to conventional brick (3 ± 0.5 MPa) [6,7].
and 1.51 gm/cc respectively as presented in Table 5. CW is lighter However at the reported compressive strength 30% shrinkage
474 D. Rajput et al. / Construction and Building Materials 34 (2012) 470–475

Table 4
Brick testing results.

Sample A B C
Volume of PW, cc 1197.3 1170.4 1143.5
Volume of cement, cc 28.44 28.44 28.44
Volume of cotton waste, cc 17.92 53.76 89.6
Volume of solid, cc 1243.66 1252.6 1261.54
Voidage 0.29 ± 0.01 0.19 ± 0.01 0.18 ± 0.01
Specific wt., gm/cc 0.56 ± 0.02 0.65 ± 0.02 0.67 ± 0.02
Dimension change on drying, % 8±1 7.5 ± 1 8±1
gm cement/gm dry PW 0.112 0.114 0.117
gm cotton waste/gm dry PW 0.011 0.034 0.058
Equilibrium moisture content, % 8.85 ± 2 8.1 ± 2 5.4 ± 2
Compressive strength, MPa 23.64 ± 0.5 22.27 ± 0.5 21.14 ± 0.5
Shrinkage on compression, % 30 ± 1 30 ± 1 30 ± 1
Water absorption, % 105 ± 5 101.6 ± 5 99.3 ± 5
Dimension change on water absorption, % 6±1 7.5 ± 1 8±1
Density gm/cc 0.598 ± 0.01 0.555 ± 0.01 0.585 ± 0.01
Efflorescence NIL NIL NIL
Thermal conductivity (W/mK) 0.25 ± 0.03 0.30 ± 0.02 0.32 ± 0.02

Table 5
Comparative study of different brick materials.

Type of brick Compressive strength (MPa) Water absorption (by weight) (%) Specific weight (gm/cm3) Reference
PW–cement 9.91 ± 0.5a 100 ± 5 0.65 ± 0.02 [4]
CW–cement 7.0 ± 0.3 17.4 ± 1.4 1.51 ± 0.00 [5]
PCW–cement 22.27 ± 0.5a 100 0.56 ± 0.02 Present work
Burnt clay brick 3.10 14.12 1.695 ± 0.02 Present work
Fly ash brick 3.12 14.64 1.750 ± 0.02 Present work
a
With 30% shrinkage.

without crack was observed. These bricks are proposed to use for homogeneity of the PCW mixture decreases. This leads to air pock-
non-load bearing internal wall structure. Bricks can be used as par- ets in the mixture and increase in voidage fraction. It is observed
tition wall and hence the shrinkage is within permissible limit. The that with increase in voidage fraction k-value increases.
bricks under compressive strength test shrunk but did not break
indicating greater tolerance for failure due to rupture. 5. Conclusion
One of the factors influencing compressive strength is amount
of fibrous material in raw materials. From sample A to C amount The physical and mechanical properties of brick samples with
of fibrous material (PW + CW) remain constant as 90% and PW, CW and cement are investigated. The test results show that
non-fibrous material (cement) as 10%. Therefore, there is not much PCW–cement combination can be potentially used in the produc-
difference in compressive strength of A, B and C. Thus compressive tion of lighter and economical brick material which can be used
strength is directly proportional to total fibrous material present. as internal partition wall. This composition produces a brick which
Results of the water absorption test indicated water absorption weighs half of that of the conventional clay brick.
was directly proportional to the CW content. This could be attrib- The observations during the tests show that bricks with 1–5%
uted to the high voidage and cellulosic nature of CW. The high addition of CW and 10% cement to PCW exhibit a compressive
water absorption of PCW can be reduced by applying water proof strength of 21–23 MPa (with 30% shrinkage) which is several times
coating over the brick surface without compromising other physi- greater than the conventional clay bricks and satisfies the require-
cal and mechanical properties of the brick material. ments for a building material to be used in the indoor structural
It was observed that the rheology of the PCW mixture changes applications. These bricks under pressure shrink but do not exhibit
as the percentage of CW increases. Higher proportion of CW im- sudden brittle fracture. Tests show that incorporation of CW in
pacts the rheology of PCW and yields non-homogeneous mixture. excess of 5% becomes difficult. From this it is concluded that 85%
With the present mixing method 5% CW was found to be optimum. PW–5% CW–10% cement is the optimum composition.
Brick making machine and raw material mixing machine are
hand operated. Hence practically there is no energy requirement
Acknowledgments
for making bricks. Per unit cost of brick is estimated to be INR
2.5. Major contribution to costing is by labor and overhead charges.
Authors gratefully acknowledge the financial support by Depart-
ment of Science and Technology, New Delhi, India for the research
project (SSD/TISN/020/2009). Authors thankfully acknowledge
4.3. Thermal properties of PCW–cement composition
guidance and suggestion of Prof K.S. Jagadish, Retired Professor,
Department of Civil Engineering, IISc Bangalore, to study thermal
Thermal conductivity (k) of all three samples was determined. k-
conductivity of building material.
Value of samples increases from A (0.25 W/mK) to C (0.32 W/mK) as
given in Table 4. k-Value is increasing with decrease in proportion
of CW in PCW. This can be explained by voidage fraction in sample. References
It is observed that with decrease in proportion of CW from 5% to 1%
[1] Raut SP, Ralegaonkar RV, Mandavgane SA. Development of sustainable
the voidage fraction decreases from 0.29 to 0.18. Fiber length of CW construction material using industrial and agricultural solid waste: a review
is greater than PW. As the proportion of CW in PCW increases the of waste-create bricks. Constr Build Mater 2011;25:4037–42.
 D. Rajput et al. / Construction and Building Materials 34 (2012) 470–475 475

[2] Huet RJ. PhD Thesis, Disposal of primary paper mill sludge on sandy cropland [5] Algin HM, Turgut P. Cotton and limestone powder wastes as brick material.
soil. University of Wisconsin-Madison; 1982. Constr Build Mater 2008;22:1074–80.
[3] Cristel Onésippe, Nady Passe-Coutrin, Fernando Toro, Silvio Delvasto, Ketty [6] Bureau of Indian Standards. Methods of tests of burnt clay building bricks. IS
Bilba, Marie-Ange Arsène. Sugar cane bagasse fibres reinforced cement 3495 (Part 1–3), New Delhi, India; 1992.
composites. Therm Consider Compos: Part A 2010;41:549–56. [7] Indian Standard: IS 1077: 1992. Common burnt clay building bricks
[4] Raut SP, Sedmake Rohant, Dhunde Sunil, Ralegaonkar RV, Mandavgane SA. specifications. New Delhi: BIS; 1992 [fifth revision].
Reuse of recycle paper mill waste in energy absorbing light weight bricks.
Constr Build Mater 2012;27:247–51.