Experimental Study on Strength Variation of

Concrete by Using Demolished Brick Aggregate

ABSTRACT

Concrete industry worldwide is drawing upon enormous natural resources and disposing large
quantities of waste construction material. This waste construction material is formed due to
demolition of obsolete structures. Natural disasters like earthquake, cyclone, flood and war-
inflicted damages Both depletion of natural resources and disposal of demolition materials are
damaging to the environment. Solution to this problem is sought in the use of demolished
concrete as aggregate for new construction. The use of such material substantially reduces the
cost of construction and saves energy required in the manufacturing process. Presently the use of
demolished concrete is restricted to lower grade application due to the lack of appropriate
specifications and mix proportioning guidelines. In Indian context a total system for use of
demolished concrete as aggregate in construction needs to develop considering all aspects like
source of demolished concrete. Aggregate preparation mix design design of structure so that it
results in a strong and durable structure. An attempt has also been made to study the performance
of recycled aggregate concrete by making a new type of concrete using 60% recycled concrete
aggregates and 40% of natural aggregates and vice-versa. The workability is also reported in
terms of compaction factor with respect to water-cement ratios of 0.50, 0.55, 0.60, and 0.65. The
workability of recycled aggregate concrete is marginally lower than that of natural aggregate
concrete at the given water-cement ratios. The study shows that the compressive strength of
recycled aggregate concrete is comparatively lower while a similar trend is reported in case of
split tensile, flexural & shear strengths at generally used water-cement ratio of 0.5. The present
investigation, which studies the strength characteristics of recycled aggregate concrete, looks
forward to popularize the use of recycled concrete as aggregates in constructions.

1
 1.INTRODUCTION
1.1 GENERAL

The construction industries require large quantities of low-cost raw materials and so
always provide opportunities for waste reuse. In big and over populated cities, old and
dilapidated structures are demolished for the purpose of building new and high- rise structures.
As a result, considerable large volume of debris and rubbles get accumulated with a serious
threat to the environment. Low lying land around the towns and cities may well be reclaimed
with this waste material. But this type of usage has been changing gradually. The continuous use
of natural resources and the consequent energy requirement for their processing has serious
economic problems.
Concrete will maintain its leading role even in the foreseeable future in the 21st century
due to a variety of its advantages chiefly amongst which are fairly durable and maintenance free
service life. Adaptability to any shape and size a wide range of structural properties and cost
effectiveness. Buildings are being demolished due to various reasons viz reconstruction for better
economic gains obsolescence due to deterioration on structural or functional performance natural
disasters and war inflicted damages The rate of demolition is increasing day-by-day and at the
same time the cost of dumping is increasing due to the non-availability of appropriate site nearby
Hence, effective reuse of the demolished concrete should be given importance which can also
lead to conservation of non-renewable natural resources. Use of demolished concern as aggregate
for concrete has potential to consume large quantity of this material. Historical Background and
Developments
It is well known that the recycled aggregate concrete was successfully used previously in
various forms of construction during the Second World War. The extensive and large scale
bombardment of cities during the Second World War left huge amount of buildings rubble and
military fortifications in most of the European countries. With the shattered economy, acute
transportation problem and no equipment to quarry aggregate, the problem of reconstruction
posed a big challenge. Further the disposal of huge amount of demolition waste was another
serious problem. As a consequence .10 these twin problems of reconstruction and disposal, the
idea of reusing demolished concrete as aggregate was considered justified as an alternative
material source in the year 1976. Consequent to this, number of European countries notably
Germany, England and Netherland made systematic attempts to reuse demolition material with
encouraging results [1].

2
 The sustainable construction concept was created a few years ago due to the growing
concern about the future of our planet. In fact the everlasting increasing amount of wastes daily
produced by industries and families demand urgent measures to reduce the amount of produced
wastes and to find viable ways of recycling for those produced. Construction industry, in
particular, is a huge waste producer and natural resource consumer, with recent estimates
indicating that almost half of the wastes of industrialised countries have their origin in
construction and demolition wastes (CDW). Simultaneously with the increasing of CDW, there is
also a growing concern with the natural resource consumption, in the case of construction
industry, mainly with natural aggregates that are rapidly diminishing. Estimates for the natural
aggregate consumption in European Union indicate 6 to 8 tons per habitant, being only inferior to
the water utilization. Impacts to the environment can be minimized by finding a way to reuse the
products/materials when they reach their lifetime, which ensures only minimal impacts to
environment, or alternatively, by extending their lifetime, thus improving their durability and
reducing resource consumption. If both things can be done at the same time, an optimal
environmental performance is attained. Environmental constrains of stone pits, such as noise,
dust, vibrations, considerable impact on the countryside, besides the consumption of a non-
renewable material tend to considerably limit their exploitation. Consequently, alternative
materials such as CDW as well as other industries by-products are increasingly being tested and
used as environmental sustainable natural aggregates substitutes. Ceramic materials are largely
used in Portugal, both as bricks and tiles. Consequently, big quantities of wastes are produced
simultaneously by the brick and tile manufacturers and by the construction industry. Most of the
wasted of the manufacturers is already incorporated as rawmaterial for new ceramic materials.
Nevertheless, part of these wastes and those produced by the construction industry are placed in
landfills. Concrete is a material that is often seen as a potential place for wastes, because of its
composite nature (a binder, water and aggregates) and because it is widely used, which means
that if a waste could be used in concrete, then certainly large quantities of the waste material are
crecycled. Regardless of several studies in this field, such as those from Poon et al. (2002),
Khalafand e DeVenny (2004a e 2004b) Brito et al. (2005), there are some questions regarding the
behaviour of concrete produced with ceramic wastes as aggregate. This uncertainty is basically
related with heterogeneity of wastes, different compositions, reduced strength of crushed brick
aggregates, lamellar shape of aggregates and so on. The aim of this work is to investigate the
effect of the replacement of natural coarse aggregate by two types of crushed bricks. Concrete is
produced by mixing cement, sand, coarse aggregate and water to produce a material that can be
molded into almost any shape. The major volume of concrete is filled with aggregate. Aggregate
inclusion in concrete reduces its drying shrinkage and improves many other properties.
3
Aggregate is also the least expensive per weight unit, put it makes the most amount of the
weight. It is costly to transport so local sources are needed, but due to geographical constraint
this is not available at all places, therefore it necessitates finding other sources and alternatives
from local sources. In eastern and north eastern states of India and Bangladesh where natural
rock deposits are scarce, burnt clay bricks are used as an alternative source of coarse aggregate.
In these places of India brick aggregate are traditionally used as coarse aggregate. The use and
performance of concrete made with broken brick as coarse aggregate are quite extensive and
satisfactory for ordinary concrete.
Articles published at that time describe these attempts and cite the first result of investigation of
aggregate made of demolition concrete. Around the year 1973 fresh research interest had come to
light in western Europe and USA in the form of articles by American authors [2]. Their renewed
research interest, developed for diverse reasons. In natural aggregate from sources close to
construction sites thereby resulting in costly transportation over long distances In other areas new
construction programmes involving replacement of old buildings made available substantial
quantities of demolished concrete, the disposal of which, posed a major problem.
Secondly there is a waste disposal problem in big-metropolitan cities. Past practice has been
to use these waste as land-fill. Since concrete accounts for about 70 per cent by weight of all
construction materials used, it follows that the disposal of concrete is becoming increasingly
difficult and expensive.
Global estimates of construction and demolition work generated annually is not
available. However, figures from the European Union indicate that between 175 to 350 million
tonnes of construction work is generated annually for a population of around 350 million. This is
equivalent to ½ to 1 tonne per capita per year. Huge amount of building waste is also generated
by natural catastrophes and wars. For example, the hurricane Andrew in August 1992 caused
damage to more than 10.000 residences in Florida and after the 1995 earth quake in Kobe. Japan,
the amount of building waste was assessed to be of the order of 20 million tones.

The last two decades of research on the concrete with aggregate from demolished
concrete has shown that it is possible to produce good quality of concrete with these aggregates.
However there are some reservations expressed with regard to certain properties of demolished
concrete aggregate when it is used for structural purposes. Comprehensive research work is in
progress at many places including India to remove these reservations and form a code of practice
to be used as guidelines A significant amount of experimental work has been carried out in the 70
s to investigate the properties of recycled aggregate concrete by Graf [2]. Buck [41 Gaede [5].
Frondistou Yannas [6] and a host of other researchers.

4
 With a view to take stock of the current level of the technology of recycled aggregate
concrete and to share the existing expertise as well as discuss the possible future developments,
an international symposium was organized by the concrete technology unit, University of
Dundee at London on November 11-12. 1998 The title under review is the proceedings of the
symposium. The symposium witnessed participation from over 70 international experts from
Europe, USA, Japan and Australia [3].

It is worthwhile to highlight the work done by DEMEX Consulting Engineers [7] who
have analyzed the prospects of systematic recycling of concrete waste in various parts of the
world In doing so, they have considered three main factors namely population size and density,
occurrence and access to raw, materials and the level of industrialisation. Based on these factors,
it is interesting to know that Dacca, Calcutta Shanghai have been rated as • profitable prospective
areas" for successful recycling of concrete waste.

1.2 Aim of Present Investigation

The purpose of present investigation is to study the various properties of concrete made with
recycled concrete as coarse aggregate. The physical and mechanical properties of concrete are,
also reported. Concrete aggregates are produced in the laboratory and can therefore be
considered as free of unsound material and contaminations. The properties of the recycled
aggregate concrete are also compared with the natural aggregate concrete. The concrete obtained
from demolition waste can be used to produce aggregate which in turn can be used for making
new concrete of acceptable quality. With the price of aggregate soaring, a reduction in
consumption of virgin aggregates would thus substantially reduce the cost construction and
would also save energy used in the manufacturing process.
The main thrust of the investigation is to evaluate aggregate obtained from field
demolition operation. A systematic study of the fresh and hardened state properties of concrete
using aggregates from demolished concrete has been undertaken. Further, it has been tried to
compare the quality of the above concrete with properties of concrete made from natural
aggregate. In this journal we are going to study on replacement of coarse aggregate by
demolished brick. Coarse aggregate can be defined as inert granular materials such as gravel,
crushed stone and sand. Coarse aggregate is one of the essential ingredients apart of water and
cement in concrete production. It consists about 60 to 75 percent of total concrete production.
Coarse aggregate comes from particles greater than 4.75 mm but commonly in a range between
9.5 mm to 37.5 mm. Therefore, the selection of coarse aggregate is vital for a good concrete mix
such as it need to be clean, tough, and strong particles that free room absorbing chemicals.
5
Furthermore, coarse aggregate also is significant due to its properties will affect the modulus of
elasticity. Determining the suitability of brick waste as alternative coarse aggregate in concrete is
very important for these researches convince people that brick waste material can be reused in
the construction process. The analysis of the test is required to identify the result whether it is
satisfactory the requirement or not. This is due to result from the test will show that whether
brick waste can achieve the minimum required for compressive strength test and even higher.
The compressive strength will be present for age 7 and 28 days, respectively. The test to identify
physical and mechanical properties of brick waste concrete is vital to improvisation the
properties of coarse aggregate by brick waste alternative in concrete production. By carrying on
the flexural strength test, the ability of concrete to resist distortion under load can be set. We can
conclude that how many in per cent brick waste is needed to make its properties in brick concrete
strong and can achieve the resistance to deformation load

6
 2.LITERATURE REVIEW
2.1 GENERAL

Akhtaruzzaman and Hasnat [2] investigated the various engineering properties of concrete
using crushed brick as coarse aggregate. Khaloo [3] studied the properties of concrete using
crushed clinker brick as coarse aggregate. In both the above-mentioned studies, investigations
were also done by comparing the properties of brick aggregate concrete with those for stone
aggregate concrete.
Rashid et al. [1] investigated the properties of higher strength concrete with brick aggregate. On
the other hand, studies were done by Mansur et al. [4] comparing the properties of stone
aggregate concrete with those of equivalent brick aggregate concrete obtained by replacing stone
with an equal volume of crushed brick, everything else remaining the same. Cachim [5] studied
the mechanical properties brick aggregate concrete by partial replacement of natural stone
aggregate by brick aggregate and it was found that upto 15% replacement there is no reduction of
strength.
Debieb and Kenai [6] showed that it is possible to produce concrete containing crushed bricks
(coarse and fine) with characteristics similar to those of natural aggregate concrete provided that
the percentage of brick aggregates is limited to 25 and 50% for the coarse and fine aggregate
respectively. Apart from strength parameter in ambient temperature Khalaf and DeVenny [7]
studied the thermal properties of brick aggregate concrete and it was found that brick aggregate
concrete perform similar and even better than granite aggregate concrete in elevated temperature
Abdullah Anwar et al.[2] teammates stated that marble dust powder is now days intensely
focused research topic in which many problem related to environmental well as civil engineering
are associated. They stated that Marble dust powder is settled by alleviation then drop away,
which end up in environmental contamination, additionally to forming dust in summer and
threatening each agriculture and public goodness. They replaced (OPC & PPC) cement
consequently within the reach of 1/3, 5%, 10%, 15% 20%, & twenty fifth by weight of M-20
grade concrete & concrete mixtures were developed, tested and compared in terms of
compressive strength to the conventional concrete. The aim of their investigation was to analyze
the behavior of concrete while replacing the Marble Dust Powder with Different proportions in
concrete.

7
Osman Simsek et al. [3] mates investigated that the sulphate resistance of cement mortars when
subjected to different exposure conditions. They added that cement mortars were prepared using
ground waste brick (GWB) as a Pozzolanic partial replacement for cement at replacement levels
of 0%, 2.5%, 5%, 7.5, 10%, 12.5 and 15% & mortar specimens were stored under three different
conditions: continuous curing in lime-saturated tab water (TW), continuous exposure to 5%
sodium sulphate solution (SS), and continuous exposure to 5% ammonium nitrate solution (AN),
at a temperature of 20 ± 3 ºC, for 7, 28, 90, and 180 days. They also stated that prisms with
dimensions of 25×25×285 mm, to determine the expansions of the mortar samples; and another
set of prisms with dimensions of 40×40×160 mm, were prepared to calculate the compressive
strength of the samples & it was determined that the GWB replacement ratios between 2.5% and
10% decreased the 180 days expansion values. They concluded that the highest compressive
strength values were found for the samples with 10% replacement ratio in the TW, SS, and AN
conditions for 180 days & the microstructure of the mortars were investigated using scanning
electron microscopy (SEM) and the Energy dispersive X-ray (EDX).
Amitkumar D. Raval et al. [4] investigated that the ceramic industry inevitably generates
wastes, irrespective of the improvements introduced in manufacturing processes & about 15%-
30% production goes as waste. They stated that these wastes pose a problem in present-day
society, requiring a suitable form of management in order to achieve sustainable development. In
their research study, they replaced (OPC) cement by ceramic waste powder accordingly in the
range of 0%, 10%, 20%, 30% 40%, & 50% by weight for M-25 grade concrete & the wastes
employed came from ceramic industry which had been deemed unfit for sale due to a variety of
reasons, including dimensional or mechanical defects, or defects in the firing process. They
concluded that the use ceramic masonry rubble as active addition endows cement with positive
characteristics as major mechanical strength and the economic advantages & reuse of this kind of
waste has advantages economic and environmental, reduction in the number of natural spaces
employed as refuse dumps.
Ankit Nileshchandra Patel et al. [5] researched that stone waste is one of the most active
research areas that encompass a number of disciplines including civil engineering and
construction materials. They stated that the stone dust is settled by sedimentation and then
dumped away which results in environmental pollution, in addition to forming dust in summer
and threatening both agriculture and public health & therefore, utilization of the stone dust in
various industrial sectors especially the construction, agriculture, glass and paper industries
would help to protect the environment. They stated that, it is most essential to develop eco-
friendly concrete from stone waste & in their research study, the (PPC) cement has been replaced
by stone waste accordingly in the range of 0%, 10%, 20%, 30% 40%, & 50% by weight for M-25
grade concrete & concrete mixtures were produced, tested and compared in terms of workability
8
and strength to the conventional concrete. These tests were carried out to evaluate the mechanical
properties for 7, 14 and 28 days & as a result, the compressive strength increased up to 20%
replacing of stone waste. This research work is concerned with the experimental investigation on
strength of concrete and optimum percentage of the partial replacement by replacing (PPC)
cement via 0%, 10%, 20%, 30%, 40% and 50% of stone waste. The aim of their investigation
was to check the behavior of concrete while replacing of waste with different proportions of
stone waste in concrete by using tests like compression strength.
Candra Aditya et al. [6] researched on alternative materials primarily from waste have been
additional material at area manufacture of building materials, especially concrete roof tile. Their
research would expand utilization of marble waste in East Java region of Indonesia in the
manufacture of concrete roof tiles by combining the use of sand and waste marble powder as a
substitute for river sand and portland cement. Their research would create a material innovation
product of environmentally friendly with relatively low prices without compromising quality.
The purpose of their research was to find the composition of the mixed-use waste marble tile that
produces the most optimal strength & experimental method used in this study to test the basic
material and test physical and mechanical properties of concrete roof tiles ( bending loads , water
absorption and resistance to water seepage ) in accordance with ISO 0096 :2007 with eight
variations in material composition .They stated that the concrete tile with marble waste produces
a lighter weight 3.6 % - 12.3 % & replacement of PC with marble powder by 20 % qualify
flexural strength , water absorption ( no more than 10 % ) and there is no seepage within 20
hours ± 5 minutes .They concluded that composition tile marble concrete using waste as a
substitute for river sand PC and a decent and qualified SNI 0096:2007 is a composition of 0.8 PC
: 0.2 SL : 1 Ps : 2 PSL and composition 0.8 PC : 0.2 SL: 3 PSL , while most optimum is 0.8
composition PC : 0.2 SL :1 Ps : 2 PSL . which produces Flexture1141 N.
Mohammad Alizadeh Kharaazia et al. [8] studied that the abrasion resistance of concrete
proportioned to have four levels of fine aggregate replacement (10%, 20%, 30%, and 40%) with
Class F fly ash. They designed a control mixture with ordinary Portland cement to have 28 days
compressive strength of 26 MPa & specimens were subjected to abrasion testing in accordance
with Indian Standard Specifications (IS: 1237). They performed tests also for fresh concrete
properties and compressive strength as well as tests on compressive strength and abrasion were
performed up to 365 days by them. C Meyer et al. [9] studied that the reuse of waste glass poses
a major problem in large municipal areas of the United States. They stated that the post-
consumer glass is often mixed-color and commingled with plastics and metals, contaminated
with other materials like ceramics and organic matter and partially broken & this reduces its
value and complicates the ability to achieve the cullet specifications of bottle manufacturers or
other markets such as the construction industry. They studied that most of these markets make
9
little use of the inherent chemical and physical properties of glass; therefore its market value is
very low. they investigated that specific products such as paving stones, concrete masonry
blocks, terrazzo tiles, and precast concrete panels are close to commercial production. In their
research, they concluded the various steps that need to be taken by recyclers like to collect the
glass, separate it from the other materials, clean it and crush it to obtain the appropriate grading
to meet the specifications for specific applications.
Sudhir S. Kapgate et al. [10] studied that the concrete plays the key role and a large quantum of
concrete is being utilized in every construction practices. They also studied that natural river sand
is one of the key ingredients of concrete, is becoming expensive due to excessive cost of
transportation from sources & also large scale depletion of sources creates environmental
problems & to overcome these problems there is a need of cost effective alternative and
innovative materials. They studied deeply & stated that Quarry dust is as waste obtained during
quarrying process & it has very recently gained good attention to be used as an effective filler
material instead of fine aggregate & also, the use of quarry dust as the fine aggregate decreases
the cost of concrete production in terms of the partial replacement for natural river sand. They
formed the design mix of M25grade concrete with replacement of 0%, 20%, 25%, 30%, and 35%
of quarry dust organized as M1, M2, M3, M4 and M5 respectively have been considered for
laboratory analysis viz. slump test, compaction factor test, compressive strength ,split tensile
strength and flexural strength of hardened concrete. They investigated the hardened properties of
concrete using quarry dust.
Siddesha H et al. [11] studied that increased construction activity and continuous dependence
on conventional materials of concrete making are leading to scarcity of the construction material
and increased construction cost. In this study, he has made an attempt to find the suitability of
ceramic fine aggregate as a possible substitute for conventional fine aggregate in concrete. He
carried out experiments to determine the compressive, split tensile and flexural strength of
ceramic fine aggregate and comparison is made with conventional concrete. He concluded that,
the properties of ceramic fine aggregate are well within the range of values of concrete making
aggregates.

10
 3. MATERIALS

3.1 INTRODUCTION
In this chapter, materials properties and concrete mix design calculations for M20 grade
concrete in detail was presented. Mix design summary for M30 under study are covered in this
chapter.
3.2 MATERIALS AND THEIR PROPERTIES
Raw materials required for the concrete use in the present work are
• Cement
• Aggregates
• Brick aggregate
• Water
3.3 ORDINARY PORTLAND CEMENT
Ordinary Portland cement is used for general constructions. The raw materials
required for manufacture of Portland cement are calcareous materials, such as limestone or chalk
and argillaceous materials such as shale or clay. The manufacture of cement consists of grinding
the raw materials, mixing them intimately in certain proportions depending upon their purity and
composition and burning them in a kiln at a temperature of about 13000C to 15000C at which
temperature, the material sinters and partially fuses to form nodular shaped clinker. The clinker is
cooled and ground to a fine powder with addition of about 2 to 3% of gypsum. The product
formed by using the procedure is a “Portland cement”. Ordinary Portland cement-53 grade have
used in the investigation. The cement was tested according to IS 4031:1988. It confirmed to IS
12269:1987.

3.4 AGGREGATES
Aggregates are the important constituents in concrete. They give body to the
concrete, reduce shrinkage and effect economy. Aggregates occupy 70 to 80 percent of volume
of concrete. Aggregates are obtained either naturally or artificially. Aggregates can be classified
on the basis of size as fine aggregate and coarse aggregate .Clean and dry river sand available

11
locally was used. Sand confirming to Zone-II. Specific gravity and fineness modulus is 2.65 and
3.15 respectively.

3.4.1 Fine aggregate (sand)

Foundry sand consists primarily of clean, uniformly sized, high-quality silica sand or lake
sand that is bonded to form molds for ferrous (iron and steel) and nonferrous (copper, aluminum,
brass) metal castings. Although these sands are clean prior to use, after casting they may contain
Ferrous (iron and steel) industries account for approximately 95 percent of foundry sand used for
castings. The automotive industry and its parts suppliers are the major generators of foundry
sand.

The most common casting process used in the foundry industry is the sand cast system. Virtually
all sand cast molds for ferrous castings are of the green sand type. Green sand consists of high-
quality silica sand, about 10 percent bentonite clay (as the binder), 2 to 5 percent water and about
5 percent sea coal (a carbonaceous mold additive to improve casting finish). The type of metal
being cast determines which additives and what gradation of sand is used. The green sand used in
the process constitutes upwards of 90 percent of the molding materials used.(1)

In addition to green sand molds, chemically bonded sand cast systems are also used. These
systems involve the use of one or more organic binders (usually proprietary) in conjunction with
catalysts and different hardening/setting procedures. Foundry sand makes up about 97 percent of
this mixture. Chemically bonded systems are most often used for "cores" (used to produce
cavities that are not practical to produce by normal molding operations) and for molds for
nonferrous castings.

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3.4.2 Coarse Aggregate
The material whose particles are of size are retained on IS sieve of size 4.75mm is termed
as coarse aggregate and containing only so much finer material as is permitted for the various
types described in IS: 383-1970 is considered as coarse aggregate.
Aggregates are the major ingredients of concrete. They constitute 70-80% of the total volume,
provide a rigid skeleton structure for concrete, and act as economical space fillers. Because at
least three-quarters of the volume of the concrete is occupied by aggregate, it is not surprising
that its quality is of considerable importance. The properties of aggregate greatly affect the
durability and structural performance of concrete. Aggregate was originally viewed as an inert
material dispersed throughout the cement paste largely for economic reasons. It is possible,
however, to take an opposite view and to look on aggregate as a building material connected in to
a cohesive whole by means of the cement paste, in a manner similar to masonry construction. In
fact, aggregate is not truly inert and its physical, thermal and sometimes also chemical properties
influence the performance of concrete. Aggregate is cheaper than cement and it is, therefore,
economical to put in to the mix as much of the former and as little of the later possible. But
economy is not only the reason for using aggregate, it confers considerable technical advantages
on concrete, which has a higher volume stability and better durability than hydrated cement paste
alone

13
3.4.3 BRICK AGGREGATE
Recycled aggregates were ceramic bricks, from two local industries, that were crushed to obtain
suitable sizes for using in concrete. As can be seen from Table 1, the final grading, of both types
of crushed bricks was very similar. Coarse to medium grained particulate material used in
construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic
aggregates. Aggregates are the most mined materials in the world. Aggregates are a component
of composite materials such as concrete and asphalt concrete; the aggregate serves as
reinforcement to add strength to the overall composite material. Due to the relatively high
hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage
applications such as foundation and French drains, septic drain fields, retaining wall drains, and
roadside edge drains. Aggregates are also used as base material under foundations, roads, and
railroads. In other words, aggregates are used as a stable foundation or road/rail base with
predictable, uniform properties (e.g. to help prevent differential settling under the road or
building), or as a low-cost extender that binds with more expensive cement or asphalt to form
concrete.

14
4.4.4 WATER
This is the least expensive but most important ingredient of concrete. The quantity and
quality of water is required to be looked in to very carefully. In practice very often great control
on the properties of all other ingredients is exercised, but the control on the quality of the water is
often neglected. Since quality of the water effects strength, it is necessary for us to go in to the
purity and quality of water. The water, which is used for making solution, should be clean and
free from harmful impurities such as oil, alkali, acid, etc. in general, the distilled water should be
used for making solution in laboratories. Water containing less than 2000 milligrams per litre of
total dissolved solids can generally be used satisfactorily for making concrete. Although higher
concentration is not always harmful they may affect certain cements adversely and should be
avoided where possible. A good thumb rule to follow is, if water is pure enough for drinking it is
suitable for mixing concrete.

15
4.5 TESTS ON CONCRETE

4.5.1 Testing On Cement

The following tests as per IS: 4031-1988 is done to ascertain the physical properties of
the cement. The results of the tests are compared to the specified values of IS: 4031-1988.

4.5.2 Consistency

The standard consistency of cement paste is defined as consistency, which will permit the
Vicat plunger to penetrate to a point 5-7 mm from the bottom of the mould, this test is done to
determine the quantity of water required to produce cement paste of standard consistency. For
determining the setting time, compressive strength and soundness, the percentage of water
required to produce cement paste of normal consistency is used. Consistency depends upon the
composition of cement, this test was conducted as per the procedure given in IS: 4031-1988. The
consistency value obtained is shown in table 3.3.

4.5.3 Initial and Final Setting Time

Lower the needle gently and bring it in contact with the surface of the test block and quickly
release. Allow it to penetrate into the test block. In the beginning, the needle will completely
pierce through the test block. But after some time when the paste starts losing its plasticity, the
needle may penetrate only to a depth of 33-35mm from the top. The period elapsing between the
time when water is added to the cement at the time of which the needle penetrates the test block
to a depth equal to 33-35mm from the top is taken as initial setting time.
Replace the needle of the Vicat apparatus by a circular attachment. The cement shall be
considered as finally set when, lowering the attachment gently cover the surface of the test block,
the centre needle makes an impression, while the circular edge of the attachment fails to do so. In
other words the paste has attained such hardness that the centre needle does not pierce through
the paste more than 0.5mm.
4.5.4 Tests On Fine Aggregate

16
 The fine aggregate shall consist of natural sand or, subject to approval, other inert
materials with similar characteristics, or combinations having hard, strong, durable particles. The
use of concrete is being constrained by urbanization, zoning regulations, increased cost and
environmental concern. The following tests have been conducted on fine aggregates.

 Specific Gravity

 Bulk density

 Sieve analysis (fineness modulus)

4.5.5 Specific Gravity

Specific Gravity is defined as the ratio of mass of material to the mass of the same volume of
water at the stated temperature. The experiment was conducted as per IS: 2386-1963 and the
values are tabulated in table-3.2.

4.5.6 Bulk Density

Bulk density is defined as mass of material to the volume of the container. The experiment was
conducted and the values are tabulated in table-3.2.

4.5.7 Sieve Analysis

The process of dividing a sample of aggregates into fractions of same particle size is known as a
sieve analysis and its purpose is to find fineness. The sieve analysis was carried out using locally
available river sand and tabulated in table 3.2.

Table 3.2 Physical properties of fine aggregate

S. No Property Value
1 Specific gravity 2.57
2 Fineness modulus 2.46
3 Bulk density:

Loose 15kN/m3

Compacted 16kN/m3
4 Grading Zone-II

17
Table 3.3 Sieve Analysis of Fine Aggregate

Sieve Cumulative
Retained % retained %passed
size % retained

10mm ----- ----- ----- 100

4.75mm 55 5.5 5.5 94.5

2.36mm 67.16 6.716 12.216 87.784
1.18mm 150 15 27.216 72.784
600µ 180 18 45.216 54.784
300 µ 306 30.6 75.816 24.184
150 µ 54.6 5.46 81.276 18.724
Pan 187 18.7 100 0
Fineness modulus = sum of % of cumulative weight retained / 100

= 347.24/100

= 3.47

4.6 Test On Coarse Aggregate

Aggregates should be of uniform quality with respect to shape and grading. The size of coarse
aggregated depends upon the nature of the work. The coarse aggregate used in this experimental
investigation is 20mm and 10mm size, crushed and angular in shape. The aggregates are free
from dust before used in the concrete.
The following tests have been conducted on coarse aggregates.
 Specific Gravity

 Fineness modulus

 Bulk density

 Sieve analysis

4.7 Specific gravity

18
Specific Gravity is defined as the ratio of mass of material to the mass of the same volume of
water at the stated temperature. The experiment was conducted as per IS 2386-1963 and the
values are tabulated in table-3.4.

4.8 Sieve Analysis (Fineness Modulus)

The process of dividing a sample of aggregates into fractions of same particle size is known as a
sieve analysis and its purpose is to find fineness. The sieve analysis was carried out using locally
available river sand and tabulated in table 3.4.

3.4.2.3 Bulk Density

Bulk density is defined as mass of material to the volume of the container. The experiment was
conducted and the values are tabulated in table-3.4.

Table 3.4 Physical properties of coarse aggregate

S. No Property Value
1 Specific gravity 2.78
2 Fineness modulus 8.83
3 Bulk density
Loose 14 kN/m3
Compacted 16 kN/m3

4 Nominal maximum size 20 mm

Table 3.5 Sieve analysis of coarse aggregate

On a sample 10kg coarse aggregate

Weight % Weight Cumulative % Weight

Sieve size
Retained retained Retained
20mm 1.76 17.6 17.6
16mm 5.50 55.0 72.6
12.5mm 2.10 21.0 93.6
10.0mm 0.61 6.1 99.7
4.75mm 0.03 0.3 100
300 µ --- --- 100
150 µ --- --- 100
Pan --- --- 100
Total 10.0 kg 683.5

Fineness Modulus =

19
 = 683.5/100
= 6.835

5. METHODOLOGY OF EXPERIMENT

5.1 INTRODUCTION

The process of selecting suitable ingredients of concrete and determining their relative
amounts with the objective of producing a concrete of the required, strength, durability, and
workability as economically as possible, is termed the concrete mix design. The proportioning of
ingredients of concrete is governed by the required performance of concrete in two states, namely
the plastic and the hardened states. If the plastic concrete is not workable, it cannot be properly
placed and compacted. The property of workability, therefore, becomes of vital importance.

The compressive strength of hardened concrete which is generally considered to be an

index of its other properties, depending upon many factors, e.g. w/c ratio quality and quantity of
cement, water, aggregate, batching, placing, compaction and curing. The cost of concrete is made
up of the cost of material, plant and labour. The variation in the cost of material arise from the
fact that the cement is several times costly than the aggregates, thus the aim is to produce as lean
a mix as possible.

The actual cost of concrete is related to the cost of materials required for producing a
minimum mean strength called characteristic strength that is specified by the designer of the
structure. This depends on the quality control measures, but there is no doubt that the quality
control adds to the cost of concrete. The cost of labour depends on the workability of mix.

5.2 REQUIREMENTS OF CONCRETE MIX DESIGN

The requirements which form the basis of selection and proportioning of mix ingredients are:

a) The minimum compressive strength required from structural consideration

b) The adequate workability necessary for full compaction with the compacting equipment
available.

c) Maximum water-cement ratio to give adequate durability for the particular site
conditions.

d) Maximum cement content to avoid shrinkage cracking due to temperature cycle in mass
concrete.

Factors to be considered for mix design

20
• The grade designation, (the characteristic strength requirement of concrete).

• The type of cement influences the rate of development of compressive strength of

concrete.

• Maximum nominal size of aggregates to be used in concrete may be as large as possible

within the limits prescribed by IS: 456-2000

• The cement content is to be limited from shrinkage, cracking and creep.

• The workability of concrete for satisfactory placing and compaction is related to the
shape and size.

5.3 Stipulation for Proportioning Concrete Ingredients

(a) Characteristic compressive strength required in the field at 28 days grade designation -

M 30

(b) Type of Cement       :           OPC 53 Grade confirming to IS 12269

(b) Maximum Nominal size of aggregate   — 20 mm

(c) Shape of CA — Angular

(d) Workability required at site — 100 mm (slump)

(e) Type of exposure the structure will be subjected to (as defined in IS: 456) — Moderate

(h) Method of concrete placing: pumpable concrete

(ii) Test data of material

The following materials are to be tested in the laboratory and results are to be ascertained for
the design mix

(a) Cement Used                                :           OPC 53 Grade Confirming to IS 12269

(b) Specific Gravity of Cement         :           3.15

(c) Chemical admixture                    :           Super plasticizer confirming to IS 9103

(d) Specific gravity

Specific gravity of Fine Aggregate (sand)   :           2.70

Specific gravity of Coarse Aggregate          :           2.80

(e) Water Absorption

21
Coarse Aggregate                                         :           0.4%

Fine Aggregate                                             :           1.0%

(f) Free (surface) moisture

Coarse Aggregate                                          :           Nil

Fine Aggregate                                              :           Nil

Aggregate are assumed to be in saturated surface dry condition usually while preparing
design mix.

(g) Sieve Analysis

Fine aggregates                                                 :   Confirming to Zone I of Table 4 IS – 383

Mix Design of M30 Grade Concrete

Step 1: Determining the Target Strength for Mix Proportioning

Fck = fck + 1.65 x S

Where,

Fck = Target average compressive strength at 28 days

fck = Characteristic compressive strength at 28 days

S = Assumed standard deviation in N/mm2 = 5 (as per table -1 of IS 10262- 2009)

= 30 + 1.65 x 5.0 = 38.25 N/mm 2

22
Step 2: Selection of water-cement ratio:-

From Table 5 of IS 456, Maximum water-cement ratio = 0.50

Note: Do not start with w/c ratio above 0.50, even though the other desired results like
Strength, workability could be achieved.

Take water cement ratio =0.4

Step 3: Selection of Water Content

Maximum water content for 20 mm aggregate = 186 Kg (for 25 to 50 slump)

23
We are targeting a slump of 100mm, we need to increase water content by 3% for every
25mm above 50 mm i.e. increase 6% for 100mm slump

I.e. Estimated water content for 100 Slump = 186+ (6/100) X 186 = 197litres

Water content = 197 liters

STEP 4 – Calculation of Cement Content

Water-Cement Ratio                         = 0.4

Water content from Step – 3 i.e. 197 liters

Cement Content = Water content / “w-c ratio” = (197/0.40) = 492 kgs

From Table 5 of IS 456,

Minimum cement Content for moderate exposure condition = 320 kg/m3

492.5 kg/m3 > 320 kg/m3, hence, OK.

STEP 5: Proportion of Volume of Coarse Aggregate and Fine aggregate Content

From Table 3 of IS 10262- 2009, Volume of coarse aggregate corresponding to 20 mm size
and fine aggregate (Zone I) = 0.60

Note 1: In the present case water-cement ratio is 0.5.So there will be no change in coarse
aggregate volume i.e. 0.60.

24
Note 2: Incase the coarse aggregate is not angular one, then also volume of coarse aggregate
may be required to be increased suitably based on experience.

Correction vol w/c

-0.01 +0.05

+0.01 -0.05

Vol of coarse aggregate =0.60+0.02=0.62

For pumpable concrete reduce 10% of coarse aggregate =0.62*0.9=0.558

Vol of fine aggregate content = 1-0..558=0.442

STEP 6: Estimation of Concrete Mix Calculations

The mix calculations per unit volume of concrete shall be as follows:

1. Volume of concrete = 1 m3

2. Volume of cement = (Mass of cement / Specific gravity of cement) x (1/1000)

= (492.5/3.15) x (1/1000) = 0.156 m3

3. Volume of water = (Mass of water / Specific gravity of water) x (1/1000)

= (197/1) x (1/1000) = 0.197 m3

4. Total Volume of Aggregates = 1- (b+c) =1- (0.15619 +0.197) = 0.647m3

5. Mass of coarse aggregates = d X Volume of Coarse Aggregate X Specific Gravity of

Coarse Aggregate X 1000

= 0.647 X 0.558 X 2.70 X 1000

= 974.7702 kgs/m3

Mass of fine aggregates = d X Volume of Fine Aggregate X Specific Gravity of

Coarse Aggregate X 1000

= 0.647 X 0.442 X 2.70 X 1000 = 772.129 kgs/m3

25
STEP-7: Concrete Mix proportions for Trial Number 1

Cement = 492 kg/m3

Water = 197 kg/m3

Fine aggregates = 772.13 kg/m3

Coarse aggregate = 974.77 kg/m3

Water-cement ratio = 0.50

Final trial mix for M30 grade concrete is 1:1.57:1.98 at w/c of 0.50

6. EXPERIMENTAL PROGRAMME

6.1 General
The experiments were conducted in laboratory of GUNTUR ENGINEERING COLLEGE in
Guntur.
6.2 Casting of Concrete Cubes, Cylinders
The check moulds were unbroken prepared before getting ready the combination. Moulds
were cleansed and oiled on all contacts surfaces. The concrete is stuffed into moulds in 3 layers
then compacted with tamping rod. the highest surface of concrete is stricken off to level with a
trowel. the quantity and date of casting were placed on the highest surface of the cubes, cylinders
and cubes.
The coarse combination was unbroken utterly immersed in clean water for twenty-
four hours for water absorption. when twenty four hours, the mixture was gently surface dried. it
absolutely was then detached and exposed to the atmosphere till it seems to be utterly surface
dry. For fine combination, considering the massive time to be taken to become surface dry from
wet condition, it absolutely was not immersed in water. Instead the water was wet then it
absolutely was detached and exposed to the atmosphere till it seems to be utterly surface dry.

26
6.3 Batching
Batching means that measurement the quantities of constituents of concrete needed for
the preparation of concrete combine. Weight batch methodology is adopted to live the quantities.
The quantities of fine combination, coarse combination, cement, water, for every batch were
measured by a balance in step with the combination proportions obtained by the combination
adopted style.
6.4 Mixing
the article mixing} is to coat the surface of all combination particles with Cement paste and to
blend all the ingredients of concrete into a consistent mass. tho' intermixture of the materials is
important for the assembly of uniform concrete. the blending ought to make sure that the mass
becomes same, uniform in color and consistency. during this study the method of machine
intermixture was adopted
6.5 Casting of Concrete Cubes, Cylinders and Cubes
The check moulds were unbroken prepared before making ready the combo. Moulds were
clean and oiled on all contacts surfaces. The concrete is stuffed into moulds in 3 layers and so
compacted with tamping rod. the highest surface of concrete is smitten off to level with a trowel.
the quantity and date of casting were placed on the highest surface of the cubes, cylinders and
cubes.
6.6 curing:
The forged moulds international organisationit|square measure} dried then the moulds
square measure un moulded, then cubes, cylinders and beams were unbroken for hardening in
potable water.
6.7 WORKABILITY
Workability could be a property of recent concrete. It is, however, additionally a
significant property as so much because the finished product is bothered as a result of concrete
should have workability specified compaction to most density is feasible with an affordable
quantity of labor or with the number that we have a tendency to ready to place in below given
conditions.
According to ACI, workability is that property of the freshly mixed concrete or mortar that
determines the benefit and homogeneity with that it will be mixed, placed, consolidated and
finished.
Workability of the concrete will be measured in many ways. Here, workability in terms of
slump and compaction issue was thought-about for this study.

27
6.7.1 Slump Cone Test
This test is used extensively in site all over the world. The slump test does not measure
the workability of concrete, but the test is very useful in detecting variations in the uniformity of
a mix of given nominal proportions.
The slump test is done as prescribed by IS: 516.
The apparatus for conducting the slump test essential consists of a metallic mould in the form of
a cone having the internal dimensions as under
Bottom diameter : 200 mm
Top diameter : 100 mm
The mould for slump is a frustum of a cone, 300 mm high. It is placed on a smooth
surface with the smaller opening at the top, and filled with concrete in three layers. Each layer is
tamped twenty five times with a standard 16 mm diameter steel rod, rounded at the end, and the
top surface is struck off by means of sawing and rolling motion of the tamping rod. The mould
must be firmly fixed against its base during the entire operation; this is facilitated by handles or
foot-rests brazed to the mould. Immediately after filling, the cone is slowly lifted vertically up,
and the unsupported concrete will now slump – hence the name of the test. The difference in
level between the height of the mould and that of highest point of subsided concrete is measured.
This difference in height in mm is taken as slump of concrete.

6.8 HARDENED PROPERTIES OF CONCRETE

6.8.1 Compression Test according to IS: 516-1959

Compression test was conducted on 150mm×150mm×150mm cubes. Concrete specimens
were removed from curing tank and cleaned. In the testing machine, the cube is placed with the
cast faces at right angles to that of compressive faces, then load is applied at a constant rate of 1.4

28
kg/cm2/minute up to failure and the ultimate load is noted. The load is increased until the
specimen fails and the maximum load is recorded. The compression tests were carried out at 7,
28, 56 days. For strength computation, the average load of three specimens is considered for each
mix. The average of three specimens was reported as the cube compressive of strength.

Cube compressive strength = Load/ Cross sectional area

6.9 Split tensile strength test according to IS: 516-1999

The cylinder specimen is of the size 150 mm diameters and 300mm length. The test is
carried out by placing a cylindrical specimen horizontally between the loading surfaces of
compression testing machine and the load is applied until failure of cylinder, along its
longitudinal direction. The cylinder specimens are tested at 7 days, 28 days and 56 days. The
average of three specimens was reported as the split tensile strength.

Split tensile strength =

Where
P = compressive load on the cylinder.
L=length of the cylinder.
D=diameter of the cylinder

29
30
 7 RESULTS AND DISCUSSION OF RESULTS

7.1 Workability of Natural and Recycled Aggregate Concrete

As the aggregates were used in dry state condition in the summer season, therefore the e
minimum amount of water was absorbed by the aggregates and no free water was present on
surface of the aggregates. Workability was measured in terms of compaction factor only. As a
general phenomenon, the workability of concrete made with natural aggregates, increases as the
W/C ratio increases, while it does not increase so sharply in case of fully and partially recycled
aggregate concrete. It is clear that fully recycled and partial recycled aggregate concrete has
minimum workability at W/C ratio of 0.5 because water absorption capacity of recycled
aggregate was much higher than the natural aggregates. So the residual water might not be
sufficient for proper compaction in green state at lower W/C ratio of 0.50.

S.no % RBA+ % NA (Mix ID) Slump in mm

1 40% RBA + 10% NA 60
2 40% RBA + 20% NA 50
3 40% RBA + 30% NA 50
4 40% RBA + 40% NA 45
5 40% RBA + 50% NA 40
6 40% RBA + 60% NA 30

31
 60

50

40

30
SLUMP
20

10

0
40%RBA+10%NA 40%RBA+40%NA

7.2 Compaction factor test

Table 5.2. Variation of Compaction Factor Test

S.no % CS + % METAKAOLIN (Mix Compaction
ID)
factor
40% RBA + 10% NA
1 0.8
40% RBA + 20% NA
2 0.84
40% RBA + 30% NA
3 0.86
40% RBA + 40% NA
4 0.9
40% RBA + 50% NA 0.8
40% RBA + 60% NA
5 0.7

32
 0.9
0.8
0.7
0.6
0.5
0.4 COMPACTION
FACTOR
0.3
0.2
0.1
0
40%RBA+10%NA 40%RBA+40%NA

33
 7.3COMPRESSION TEST according to IS: 516-1959

Compression test was conducted on 150mm×150mm×150mm cubes. Concrete specimens

were removed from curing tank and cleaned. In the testing machine, the cube is placed with the
cast faces at right angles to that of compressive faces, then load is applied at a constant rate of 1.4
kg/cm2/minute up to failure and the ultimate load is noted. The load is increased until the
specimen fails and the maximum load is recorded. The compression tests were carried out at 7,
28, 56 days. For strength computation, the average load of three specimens is considered for each
mix. The average of three specimens was reported as the cube compressive of strength.

Cube compressive strength =

compressive strength
s.no % RBA+ % NA (Mix ID)
7 days 14 days 28 days
40% RBA + 10% NA
1 18.86 25.88 29.72

40% RBA + 20% NA

2 19.94 27.21 29.96
40% RBA + 30% NA
3 21.42 28.86 30.66
40% RBA + 40% NA
4 20.86 28.6 31.18
40% RBA + 50% NA
5 20.74 28.46 30.84
40% RBA + 60% NA
6 20.70 28.40 30.70

34
 35
30
25
20 7 DAYS
15 14 DAYS
28 DAYS
10
5
0
40%RBA+10%NA 40%RBA+40%NA

7.4 Split tensile strength

Table 5.4 Split tensile strength of concrete

Split tensile strength

s.no % RBA+ % NA (Mix ID)
7 days 28 days
40% RBA + 10% NA
1 2.89 3.98
40% RBA + 20% NA
2 3.12 4.36
40% RBA + 30% NA
3 3.54 4.88
40% RBA + 40% NA
4 3.24 4.56
50 %RBA+ 50% NA
5 3.14 4.44
60% RBA + 60% NA
5 3.02 4.26

35
 6

3 7 DAYS
28 DAYS
2

0
40%RCA+10%NA 40%RCA+40%NA

8 .CONCLUSION

36
8.1 general
Based on the test results of the present investigation, the following major conclusions can be
drawn.
i) Recycled concrete as coarse aggregate can be used in place of natural aggregate for concrete of
acceptable quality for practical uses.
ii)The concrete with recycled concrete as coarse aggregate will not impose any problem in
workability in fresh state and strength development in hardened state for W/C ratio more than 0.5
for different ages.
iii)The variation of the various strengths of the concrete with age for fully and partially recycled
aggregate concrete follows the same trend as that of natural aggregate concrete.
iv)At W/C ratio above 0.5 and up to 0.6 various strength of the concrete with fully and partially
recycled aggregate concrete increase at different ages in comparison to the corresponding
strengths of concrete with natural aggregate.
v) At W/C ratio more than 0.6, the strength of concrete made with both types of aggregate
follows the same trend.

37
Scope for Further Study
The strength characteristics of recycled aggregate concrete can be further studied by taking into
account the following parameters.
1. Using different grades of cement i.e 33 and 43 grade.
2. With different types and grading of sand.
3. By varying the mix proportions.
4. By using the fine aggregate also as recycled concrete aggregate.
5. By varying the percentage of recycled and natural aggregate (Coarse as well as fine
aggregate).
Demolished concrete aggregate (recycled aggregate) possesses relatively lower bulk density and
higher water absorption as compared to natural aggregate. This is mainly due to the porous
mortar adhering to demolished concrete aggregate The aggregate crushing value of demolished
concrete aggregate gets reduced only marginally but still not exceeding the BIS specified limits.
Thus demolished concrete aggregate can be used for PCC and RC constructions. It is advisable
to carry out trial castings with demolished concrete aggregate proposed to be used in order to
arrive at the water content and mix proportions to suit the workability levels and strength
requirements respectively. Economical and environmental pressures justify consideration of this
alternative material source (i.e. aggregate from demolished concrete aggregate).

38
 9. REFERENCES

[1]. Gluzhge, P.G., "The work of Scientific Research Institutes",

"CidrotekhnicheskoyeStroitelstvo 'USSR), No. 4,April, 1946, p. 27-28 (in Russian) also
brief English Summaryin Engineer's Digest, V. 7,No. 10, 1946, p. 330.
[2]. Graf, Otto, "Crushed-Brick Cocnrete, Sand Stone Concrete and Rubble Concrete
(UberZiegelsplittbeton)", Die Bauwirtschaft (Wiesbaden), Jan-March 1948, Also
Translation No. 73-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg,
January, 1973.
[3]. Ploger, R.R., "An Investigation of the compressive Strength of Concrete in which concrete
Rubble was used as Aggregate". M.S. Thesis, Cornel University, Ithaca, 1947.
[4]. Buck, Alan, D., "Recycled Concrete as a Source of New Concrete". ACI Journal, V. 74,
No. 5, August, 1977.
[5]. Frodiston , Yams, "Waste concrete as Aggregate for new concrete, ACI Journal, V. 74, No.
5, August 1977. ,
[6]. Malhotra,4.M. "Use of Recycled concrete as a new Aggregate". Ottawa, Canada, Centre for
Mineral and Energy Technology, 1976, Report 76-78.
[7]. Ravindfarajah, R. Sri and Tam, T.C., "Proeprties of concrete made with crushed concrete
as coarse aggregate", Magazine of Concrete Research, Vol. 37, No. 130, pp. 29-38 (1985).
[8]. Nixon, P.J., "Recycled concrete as an aggregate for concrete - a review", Vol. 11, No. 65 -
Materiauxet construction. pp. 371-378.
[9]. Considerations in producing high strength concrete” (2009), Mohammad Abdur Rashid and
Mohammad Abul Mansur,Journal of Civil Engineering (IEB).
[10]. Use of recycled concrete aggregates in highstrength concrete” (2000).M.C.Limbachiya, T.
Leelavat and R.K.Dhir.Materials and Structures , Vol:33
[11]. Effectiveness of using coarse recycled aggregate in concrete”(2011),Neela
Deshpande,S.S.Kulkarni, International Journal of Earth Science and Engineering
[12]. Influence of fine stone dust on high strength concrete” August 2007,V. Syam
PrakashDhanya Krishnan,G. Jeenu,32ndConference on OUR WORLD IN CONCRETE &
STRUCTURES
[13]. IS: 456 – 2000 (Fourth Revision) Indian Standard Plain and Reinforced Concrete Code of
Practice.
[14]. IS: 383-1970 (Second Revision), Specifications for Coarse and Fine Aggregates from
Natural Resources for Concrete.

39
[15]. IS: 10262-2009 (first revision), Concrete Mix Proportioning Guidelines.
[16]. IS: 516-1959,Methods of test for strength of concrete, edition 1.2(1991-07)
[17]. M.S Shetty “Concrete Technology”, Theory and practice, S Chand 2011.
[18]. Tsung-Yueh, Yuen-Yeun Chen, Chao-Lung Hwang(2006), “Properties of HPC with
recycled aggregates”, Cement and Concrete Research, vol:36, pp943-950.
[19]. J.S.Ryu, (2002),”An experimental study on the effect of recycled aggregate on concrete
properties”, Mag. Concr. Res, Vol:54 (1), pp-7-12
[20]. A. K. Padmimi, K. Ramamurthy, M. S. Matthews (2002), “Relative moisture movement
through recycled aggregate concrete”, Cement Concrete Research, vol: 54(5), pp-377-384.

40