Strengthening of concrete block

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STRENGTHENING OF CONCRETE BLOCK
WITH THE ADDITION
OF
RUBBER SCRAP AND COCONUT SHELL
A PROJECT REPORT
Submitted by
K.RAJA SIMMAN 312814103037
R.RAKESH 312814103039
M.SAKTHIGOPAL 312814103045
K.SUBRAMANIAN 312814103047
in partial fulfilment for the award of degree
OF
BACHELOR OF ENGINEERING
IN
CIVIL ENGINEERING
AGNI COLLEGE OF TECHNOLOGY
ANNA UNIVERSITY: CHENNAI-600 025
APRIL 2018

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BONAFIDE CERTIFICATE
This is to certify that the project report entitled “ANALYSIS AND DESIGN OF
FIVE STAR HOTEL” submitted by Raja Simman.K (312814103037),Rakesh.R
(312814103039), SakthiGopal.M (312814103045), Subramanian.K
(312814103047)” to the Department of Civil Engineering, College of Engineering
Studies, Agni College Of Technology, Chennai, in partial fulfillment of the
requirements for the award of B. E Degree in Civil Engineering is a bonafide
record of work carried out by them.
SIGNATURE SIGNATURE
MR.S.Ramamoorthy.M.E,(Ph.D) Mr. Aswin Kumar.S.B.E, M.E,
PROFESSOR AND HEAD ASSISTANT PROFESSOR,
Department Of Civil Engineering Department Of Civil Engineering
Agni College of Technology Agni College of Technology
Chennai. Chennai.
Submitted for viva voice examination held on.......................................
INTERNAL EXAMINER EXTERNAL EXAMINER

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ACKNOWLEDGEMENT
“Hundred times every day we remind ourselves that our inner and outer life
are based on the labors of others” -Einstein
We are very much indebted to everyone who has contributed so much for
the successful project.
We would like to express our special gratitude and thanks to our chair
person Mrs. Bhavani Jayaprakash for providing us with the required facilities
and support towards the completion of the project.
We express our Sincere thanks to our Principal Dr. R.S.Kumar,
B.E(Hons),M Tech.,Ph.D for his kind and timely support.
We wish to express our deep sense of gratitude to our beloved Dean Dr.
Srinavasan Alavandar, M.E., Ph.D. for his constant support and for providing
constructive feedback and approval of the project.
We are most grateful to Mr.M.AswinKumar.B.E, M.E., Department of
Civil Engineering for providing us all the help needed.
We express our deep sense of gratitude to our guide Mr. S.
Ramamoorthy M.E. (Ph. D.), Associate Professor and Head, Department of
Civil Engineering, for his valuable guidance and proficient suggestion and help.
Above all, we extremely thank our parents and friends for good health,
confidence and encouragement throughout the study of the project.
K.RAJASIMMAN
R.RAKESH
M.SAKTHI GOPAL
K.SUBRAMANIAN

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ABSTRACT
The results of an experimental investigation to study the effects of partial replacement of cement
with fly ash in rubberized and coconut shell concrete. The percentage of rubber used in this study
was 5% replaced with coarse aggregate and fly ash varies from 0-20% were replaced with
cement in conventional concrete. One size of tire rubber chips are used of about 10mm.
Rubber is produced excessively worldwide every year. It cannot be discharge off easily in the
environment as its decomposition takes much time and also produces environmental pollution. In
such a case the reuse of rubber would be a better choice.
In order to reuse rubber wastes, it was added to concrete as coarse aggregate and its different
properties like compressive strength, Tensile strength, ductility etc. were investigated and
compared with ordinary concrete.
As a result it was found that rubberized concrete is durable, less ductile, has greater crack
resistance but has a low compressive strength when compared with ordinary concrete. The
compressive strength of rubberized concrete can be increased by adding some amount of silica to
it.
Properties of concrete with coconut shells (CS) as aggregate replacement were studied. Control
concrete with normal aggregate and CS concrete with 10-20% coarse aggregate replacement with
CS were made. Two mixes with CS and fly ash were also made to investigate fly ash effect on
CS replaced concretes. Constant water to cementitious ratio of 0.6 was maintained for all the
concretes. Properties like compressive strength, split tensile strength, water absorption and
moisture migration were investigated in the laboratory. The results showed that, density of the
concretes decreases with increase in CS percent.
Workability decreased with increase in CS replacement. Compressive and split tensile strengths
of CS concretes were lower than control concrete. Permeable voids, absorption and sorption
were higher for CS replaced concretes than control concrete. Coarse aggregate replacement with
equivalent weight of fly ash had no influence when compared with properties of corresponding
CS replaced concrete
The mix design was targeted to be M15 grade of concrete. The mix proportion of concrete was
1:2:4 with water cement ratio of 0.45.The fresh and hardened properties of rubberized concrete
produced at two different replacements ratios of fly ash compared to the conventional concrete
without rubber and fly ash.
The test result indicate that there was a small reduction in the strength with the 5% replacement
in rubber content as compared with the conventional concrete. However, the increase of fly ash
from 10% to 20% improved the mechanical properties of rubberized and coconut shell concrete.
This study explores the effects of rubber particles and coconut shell on some properties of
concrete.

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CONTENT
CERTIFICATE 2
ACKNOWLEDGEMENT 3
ABSTRACT 4
1.INTRODUCTION 7
1.1 INTRODUCTION OF THE PRODUCT 7
1.2 MARKET & DEMAND ASPECTS 7
1.3 OBJECTIVES 7
1.4 METHODOLOGY 8
2. MATERIALS AND METHODS 9
2.1 CEMENT 9
2.2 COARSE AGGREGATE 9
2.3 FINE AGGREGATE 9
2.4 WATER 9
2.5 COCNUT SHELL 9
2.6 RUBBER POWDER 9
3. PHYSICAL CHARACTERISTICS OF THE RUBBER POWDER 10
3.1 CHEMICAL ANALYSIS 10
3.2 DIRECT SHEAR TEST 10
3.3 PREPARATION OF TEST SPECIMENS 11
3.4 TEST 11
4. CONCRETE MIX DESIGN 12
4.1 INTRODUCTION 12
4.2 REQUIREMENTS OF CONCRETE MIX DESIGN 12
5. TEST ON FRESH CONCRETE 13
5.1 SLUMP CHART 13
6. TYPES OF MIXES 14
6.1.1 DESIGN MIX 14
6.1.2 STANDARD MIX 14
6.1.3 NOMINAL MIX 14
6.2 FACTORS AFFECTING THE CHOICE OF MIX PROPORTIONS 15
6.3 COMPRESSIVE STRENGTH 15

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6.4 WORKABILITY 15
6.5 DURABILITY 15
6.6 MAXIMUM NOMINAL SIZE OF AGGREGATE 15
6.7 GRADING AND TYPE OF AGGREGATE 15
6.8 QUALITY CONTROL 16
7. MIX PROPORTION DESIGNATIONS 17
7.1 FACTORS TO BE CONSIDERED FOR MIX DESIGN 17
7.2 MIX DESIGN FOR M15 GRADE CONCRETE 19
8. REGULAR GRADES OF CONCRETE AND THEIR USES 23
8.1 RATIO 25
8.1.1 FIRST RATIO 25
8.1.2 SECOND RATIO 25
8.1.3 CONVENTIONAL 25
8.2 STRENGTH ATTAINED 26
8.3 WATER ABSORPTION TEST 26
8.4 SPECIMEN 27
8.5 DETERMINATION OF BLOCK DENSITY 27
8.6 DETERMINATION OF WATER ABSORPTION 27
9. TESTING BLOCKS FOR COMPRESSIVE STRENGTH 29
9.1 COMPRESSION TESTING MACHINE (CTM) 29
9.2 COMPRESSIVE STRENGTH 30
9.2.1 COMPRESSIVE STRENGTH VALUE CHART 31
9.3 TEST SPECIMENS 31
9.4 CAPPING TEST SPECIMENS 31
9.4.1 ADVANTAGES 31
10.CONCLUSION 32
REFERENCE 33

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1.INTRODUCTION
Due to rapid growth of construction activities, conventional aggregate sources are depleting at a
very fast pace, leading to significant increase in cost of construction. For sustainable
development, these materials should be used wisely, and alternative cost effective and eco-
friendly materials need to be studied for its various characteristics as building materials.
Variety of waste materials, organic and inorganic has been successfully used in various building
materials such as concrete, building blocks, flush door, plywood etc. India being third largest
producer of coconut shells creates a major problem of solid waste too.
But its high strength modulus, natural shell structure and the non-biodegradable pentosans
chemical constituents’ can be utilised for using coconut shell as an alternative for coarse
aggregates, reinforcement, filler, thermal insulating material, hollow structure provider, etc., in
building blocks and concrete technology.
1.1 INTRODUCTION OF THE PRODUCT
Cement concrete hollow blocks have an important place in modern building industry. They are
cost effective and better alternative to burnt clay bricks by virtue of their good durability, fire
resistance, partial resistance to sound, thermal insulation, small dead load and high speed of
construction.
Concrete hollow blocks being usually larger in size than the normal clay building bricks and less
mortar is required, faster of construction is achieved. Also building construction with cement
concrete hollow blocks provides facility for concealing electrical conduit, water and sewer pipes
wherever so desired and requires less plastering.
1.2 MARKET & DEMAND ASPECTS
Cement concrete hollow blocks are modern construction materials and as such are used in all the
constructions viz. residential, commercial and industrial building constructions. Construction
industry is a growing a sector.
The demand for this product is always high in all cities and other urban centres due to
construction of residential apartments, commercial buildings and industrial buildings.
Growing public awareness of the advantages of the product coupled with increase in the
government and financial institutions support for housing which is a basic human necessity
would ensure a healthy growth in the demand.
1.3 OBJECTIVES
1. To study and analyse the engineering properties of Coconut shell to use it as an alternate eco-
friendly material in producing cost effective building blocks or concrete.
2. To study and evaluate the strength properties of coconut shell based concrete building blocks
viz: hollow and filled blocks with various options of shells orientations to understand its
capability to be used as a filler/composite/reinforcement material.

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1.4 METHODOLOGY:
In order to achieve these objectives, standard test such as compressive strength in dry condition
on different dome shaped coconut shells have been carried out. A suitable mix design has been
derived presuming a moderate exposure condition for the blocks.
With a mix proportion of M15 (1:2:4) concrete, standard blocks of 400mm X 200mm X 200mm
dimensions have been prepared for the analysis. About 12 hollow cubes, 6 solid cubes and 6
hollow cylinders with coconut shell as a filler and composite in different spatial orientation, and
with varying numbers/quantity have been tested for its various strength parameters such as
compressive strength, water absorption test etc., for different periods of curing.
When coconut shell aggregate and rubberized concrete is subjected to 100 ºC for 4 h and 200 ºC
for 2 h, its residual strengths are 18 N/mm2 and 18.40 N/mm2, respectively. These values satisfy
the criteria of structural lightweight concrete strength as per ASTM C 330.
Coconut shell aggregate and rubberized concrete can offer 2 hours fire resistance and therefore it
may be classified under type 3 constructions. Use of coconut shell aggregate concrete as
structural lightweight concrete is recommended. Coconut shell aggregate is a potential
construction material and simultaneously reduces the environmental problem of solid waste.
The strength increases with addition of steel fiber to the concrete with coconut shell. strength
properties decreases. The compressive strength of concrete is increased by 20% with
the addition of fibers to the concrete with coconut shells.

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2. MATERIALS AND METHODS
2.1 CEMENT
Ordinary Portland Cement (OPC) from a single source will be used throughout. Portland cement
can be defined as hydraulic cement that hardens by the interaction between its properties and that
of water which forms a water resisting compound when it receives its final set.
2.2 COARSE AGGREGATE
Aggregate has a significant influence on the compressive strength of concrete, crushed coarse
aggregate produces a concrete with higher strength than one with uncrushed coarse aggregate
(smooth and rounded aggregate). Crushed gravel of 6 mm size will be used as coarse aggregate
with a density, relative density and absorption value of 2375kg/m3, 2.7 and 0.5% respectively ml
2.3 FINE AGGREGATE
Fine aggregate refers to aggregate particles lower than 4.75 mm but larger 75mm. Fine aggregate
act as filler in concrete, fine aggregate is usually known as sand and it most complies with
coarse, medium or fine grading requirement. The fine aggregate will be air dried to obtain
saturated surface dry condition to avoid compromising water cement ratio. In this research, river
sand is used and sieve analysis will is conducted to prior to obtain fine aggregate passing through
600 μm sieve.
2.4 WATER
The chemical reaction between water and cement is very significant to achieve a cementing
property. Hydration is the chemical reaction between the compounds of cent and water yield
products that achieve the cementing property after hardening. Therefore it is necessary to that the
water used is not polluted or contain any substance that may affect the reaction between the two
components, so tap water will be used in this study.
2.5 COCONUT SHELL (CS)
They were sun dried for 1 month before being crushed manually. The crushed materials were
later being transported to the laboratory where they are washed and allowed to dry under ambient
temperature for another 1 month. The particle sizes of the coconut shell range from 10 to 14 mm.
2.6 RUBBER POWDER
Scrap tire rubber powder can be obtained from tires through two principal processes: ambient,
which is a method in which scrap tire rubber is ground or processed at or above ordinary room
temperature and cryogenic, a process that uses liquid nitrogen to freeze the scrap tire rubber until
it becomes brittle and then uses a hammer mill to shatter the frozen rubber into smooth
particles.For this study, the rubber powder was produced from three used automobile tires by
mechanical shredding at ambient temperature. Steel was removed by magnetic separation and
one part of textile fiber was removed by density.

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3. PHYSICAL CHARACTERISTICS OF THE RUBBER POWDER
The used specimens don’t contain steel but contain less than 2% of textile fiber. Since it was not
possible to determinethe gradation curve of the rubber powder as for normal aggregates, a
microscope examination was done. Dimensions of rubber powder vary from 1.6 mm to 0.8 mm
with an average particle size of 1 mm. The density of the rubber powder is determined using
helium pycnometer and it’s about 0.83. Rubber powder is also characterized by an insignificant
water absorption less than 3%.Table I resumes some characteristics of the used waste tire powder
rubber.
TABLE I. RUBBER POWDER CHARACTERISTICS
3.1 CHEMICAL ANALYSIS
The tire is made up mainly by rubber. Its constitution varies little between the car tires and heavy
truck tires. Rubber consists of a complex mixture of elastomers, polyisoprene, polybutadiene and
stirene-butadiene. Stearic acid (1.2%), zinc oxide (1.9%), extender oil (1.9%) and carbon black
(31.0%) are also important components of tires [10-11]. In Table II, chemical composition of the
used rubber powder is presented. The quantity of steel is generally about 15%, and it’s more
important for the heavy trucks tires. For this study steel and one part of textile were removed by
magnetic separation and density.
TABLE II. RUBBER POWDER CHARACTERISTICS
3.2 DIRECT SHEAR TEST
The tests were performed according to ASTM D 3080 standard.The direct shear test is a
laboratory testing method used to determine the shear strength parameters of rubber powder. To
achieve reliable results, the test is often carried out on three or four samples of rubber powder.
The sample is placed in a shear box for round specimens (60 mm diameter and 20 mm height).
The shear box is composed of an upper and lower box. The limit between the two parts of the
box is approximately at the mid height of the sample.
PROPERTIES RUBBER POWDER
Density 0.83
Size 80 μm – 1.6 mm
Elongation (%) 420
Rate of steel fiber 0%
Material/element Mass percentage
Rubber 54%
Carbon black 29%
Oxidize zinc 1%
Sulfur 1%
Additives 13%

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The sample is subjected to a controlled normal stress and the upper part of the sample is pulled
laterally at a controlled strain rate or until the sample fails. The applied lateral load and the
induced strain are recorded at given internals. These measurements are then used to plot the
stress-strain curve of the sample during the loading for the given normal stress.
Results of different tests for the same rubber powder are presented in figures with peak stress on
the horizontal axis and normal (confining) stress on the vertical axis. A linear curve fitting is
often made on the test result points. The intercept of this line with the vertical axis gives the
cohesion and its slope gives the peak friction angle.
3.3 PREPARATION OF TEST SPECIMENS
For practical consideration, specimens were separated to three gradation classes.
Class A: less than 0.08 mm
Class B: size between 1.6 mm and 1 mm
Class C: size more than 1.6 mm
3.4 TESTS
The specimens are round (60 mm diameter and 20 mm high). The realized test is an
unconsolidated un-drained test (UU). The normal constraints (normal stress) used are: 100, 200
and 300 kPa. The speed of shearing is about 0.5 mm/min. The sample is placed between two
half-boxes that can move relatively to each other. Moreover, a piston permits to exert a normal
constraint in the plan of shearing. The inferior half-box is involved horizontally at a constant
speed. The total force of shearing F is to be measured using a fixed ring at the superior half-box.

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4. CONCRETE MIX DESIGN
4.1 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 ingredient
of concrete is governed by the required performance of concrete in 2 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, depends upon many factors, e.g. quality and quantity of cement, water and
aggregates; batching and mixing; placing, compaction and curing. The cost of concrete is made
up of the cost of materials, plant and labour.
The variations in the cost of materials arise from the fact that the cement is several times costly
than the aggregate, thus the aim is to produce as lean a mix as possible. From technical point of
view the rich mixes may lead to high shrinkage and cracking in the structural concrete, and to
evolution of high heat of hydration in mass concrete which may cause cracking.
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 extent of quality control is often an economic compromise, and depends on
the size and type of job. The cost of labour depends on the workability of mix, e.g., a concrete
mix of inadequate workability may result in a high cost of labour to obtain a degree of
compaction with available equipment.
4.2 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 and/or maximum cement content to give adequate
durability for the particular site conditions
d) Maximum cement content to avoid shrinkage cracking due to temperature cycle in
mass concrete.

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5. TEST CONDUCTED ON FRESH CONCRETE
S.NO BLOCKS SLUMP VALUE (mm)
1 RATIO 1 45
2 RATIO 2 40
3 CONVENTIONAL 43.5
5.1 SLUMP CHART
37
38
39
40
41
42
43
44
45
46
RATIO 1 RATIO 2 CONVENTIONAL
SLUMP VALUE
slump value

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6. TYPES OF MIXES
6.1.1 NOMINAL MIXES
In the past the specifications for concrete prescribed the proportions of cement, fine and coarse
aggregates. These mixes of fixed cement-aggregate ratio which ensures adequate strength are
termed nominal mixes. These offer simplicity and under normal circumstances, have a margin of
strength above that specified. However, due to the variability of mix ingredients the nominal
concrete for a given workability varies widely in strength.
6.1.2 STANDARD MIXES
The nominal mixes of fixed cement-aggregate ratio (by volume) vary widely in strength and may
result in under- or over-rich mixes. For this reason, the minimum compressive strength has been
included in many specifications. These mixes are termed standard mixes.
IS 456-2000 has designated the concrete mixes into a number of grades as M10, M15, M20,
M25, M30, M35 and M40. In this designation the letter M refers to the mix and the number to
the specified 28 day cube strength of mix in N/mm2. The mixes of grades M10, M15, M20 and
M25 correspond approximately to the mix proportions (1:3:6), (1:2:4), (1:1.5:3) and (1:1:2)
respectively.
6.1.3 DESIGNED MIXES
In these mixes the performance of the concrete is specified by the designer but the mix
proportions are determined by the producer of concrete, except that the minimum cement content
can be laid down. This is most rational approach to the selection of mix proportions with specific
materials in mind possessing more or less unique characteristics.
The approach results in the production of concrete with the appropriate properties most
economically. However, the designed mix does not serve as a guide since this does not guarantee
the correct mix proportions for the prescribed performance.
For the concrete with undemanding performance nominal or standard mixes (prescribed in the
codes by quantities of dry ingredients per cubic meter and by slump) may be used only for very
small jobs, when the 28-day strength of concrete does not exceed 30 N/mm2. No control testing
is necessary reliance being placed on the masses of the ingredients.

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6.2 FACTORS AFFECTING THE CHOICE OF MIX PROPORTIONS
The various factors affecting the mix design are:
6.3 COMPRESSIVE STRENGTH
It is one of the most important properties of concrete and influences many other describable
properties of the hardened concrete. The mean compressive strength required at a specific age,
usually 28 days, determines the nominal water-cement ratio of the mix. The other factor affecting
the strength of concrete at a given age and cured at a prescribed temperature is the degree of
compaction. According to Abraham’s law the strength of fully compacted concrete is inversely
proportional to the water-cement ratio.
6.4 WORKABILITY
The degree of workability required depends on three factors. These are the size of the section to
be concreted, the amount of reinforcement, and the method of compaction to be used. For the
narrow and complicated section with numerous corners or inaccessible parts, the concrete must
have a high workability so that full compaction can be achieved with a reasonable amount of
effort. This also applies to the embedded steel sections. The desired workability depends on the
compacting equipment available at the site.
6.5 DURABILITY
The durability of concrete is its resistance to the aggressive environmental conditions. High
strength concrete is generally more durable than low strength concrete. In the situations when the
high strength is not necessary but the conditions of exposure are such that high durability is vital,
the durability requirement will determine the water-cement ratio to be used.
6.6 MAXIMUM NOMINAL SIZE OF AGGREGATE
In general, larger the maximum size of aggregate, smaller is the cement requirement for a
particular water-cement ratio, because the workability of concrete increases with increase in
maximum size of the aggregate. However, the compressive strength tends to increase with the
decrease in size of aggregate.
IS 456:2000 and IS 1343:1980 recommend that the nominal size of the aggregate should be as
large as possible.
6.7 GRADING AND TYPE OF AGGREGATE
The grading of aggregate influences the mix proportions for a specified workability and water-
cement ratio. Coarser the grading leaner will be mix which can be used. Very lean mix is not
desirable since it does not contain enough finer material to make the concrete cohesive.

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The type of aggregate influences strongly the aggregate-cement ratio for the desired workability
and stipulated water cement ratio. An important feature of a satisfactory aggregate is the
uniformity of the grading which can be achieved by mixing different size fractions.
6.8 QUALITY CONTROL
The degree of control can be estimated statistically by the variations in test results. The variation
in strength results from the variations in the properties of the mix ingredients and lack of control
of accuracy in batching, mixing, placing, curing and testing. The lower the difference between
the mean and minimum strengths of the mix lower will be the cement-content required. The
factor controlling this difference is termed as quality control.

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7. MIX PROPORTION DESIGNATIONS
The common method of expressing the proportions of ingredients of a concrete mix is in the
terms of parts or ratios of cement, fine and coarse aggregates. For e.g., a concrete mix of
proportions 1:2:4 means that cement, fine and coarse aggregate are in the ratio 1:2:4 or the mix
contains one part of cement, two parts of fine aggregate and four parts of coarse aggregate. The
proportions are either by volume or by mass. The water-cement ratio is usually expressed in
mass
7.1 FACTORS TO BE CONSIDERED FOR MIX DESIGN
 The grade designation giving 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 size and
shape of section, quantity and spacing of reinforcement and technique used for
transportation, placing and compaction.
PROCEDURE
 Determine the mean target strength ft from the specified characteristic compressive
strength at 28-day fck and the level of quality control.
ft = fck + 1.65 S
where S is the standard deviation obtained from the Table of approximate contents given after
the design mix.
 Obtain the water cement ratio for the desired mean target using the emperical relationship
between compressive strength and water cement ratio so chosen is checked against the
limiting water cement ratio. The water cement ratio so chosen is checked against the
limiting water cement ratio for the requirements of durability given in table and adopts
the lower of the two values.
 Estimate the amount of entrapped air for maximum nominal size of the aggregate from
the table.
 Select the water content, for the required workability and maximum size of aggregates
(for aggregates in saturated surface dry condition) from table.
 Determine the percentage of fine aggregate in total aggregate by absolute volume from
table for the concrete using crushed coarse aggregate.

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 Adjust the values of water content and percentage of sand as provided in the table for any
difference in workability, water cement ratio, grading of fine aggregate and for rounded
aggregate the values are given in table.
 Calculate the cement content form the water-cement ratio and the final water content as
arrived after adjustment. Check the cement against the minimum cement content from the
requirements of the durability, and greater of the two values is adopted.
 From the quantities of water and cement per unit volume of concrete and the percentage
of sand already determined in steps 6 and 7 above, calculate the content of coarse and
fine aggregates per unit volume of concrete from the following relations:
where V = absolute volume of concrete
= gross volume (1m3) minus the volume of entrapped air
Sc = specific gravity of cement
W = Mass of water per cubic metre of concrete, kg
C = mass of cement per cubic metre of concrete, kg
p = ratio of fine aggregate to total aggregate by absolute volume
fa, Ca = total masses of fine and coarse aggregates, per cubic metre of concrete,
respectively, kg, and
Sfa, Sca = specific gravities of saturated surface dry fine and coarse aggregates,
respectively
 Determine the concrete mix proportions for the first trial mix.
 Prepare the concrete using the calculated proportions and cast three cubes of 150 mm size
and test them wet after 28-days moist curing and check for the strength.
 Prepare trial mixes with suitable adjustments till the final mix proportions are arrived at.

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7.2 MIX DESIGN FOR M15 GRADE CONCRETE
M15 – M represents Mix and 15 N/mm2 is the characteristic compressive strength of concrete
cube at 28 days.
REQUIRED DATA M15 GRADE CONCRETE
Grade of concrete =M15
Characteristic compressive strength of concrete at 28days = 15N/mm2
Nominal maximum size of aggregate = 20mm
Specific Gravity of cement = 3.15
Specific gravity of fine aggregate = 2.6
Specific gravity of Coarse aggregate = 2.65
STEP 1: CALCULATION OF TARGET STRENGTH
Target mean strength of concrete is derived from the below formula
ft = fck + 1.65 s
Where S = standard deviation which is taken as per below table= 3.5
Grade of concrete Standard deviation (N/mm2)
M10 3.5
M15 3.5
M20 4.0
M25 4.0
M30 5.0
M35 5.0
M40 5.0
M45 5.0
M50 5.0
Characteristic compressive strength after 28 days fck = 15N/mm2

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ft = 15 + 1.65 x 3.5
Therefore, target mean strength ft = 20.775 N/mm2
STEP 2: SELECTION OF WATER-CEMENT RATIO
Water- cement ratio is selected from the graph plotted between 28-day compressive strength and
water-cement ratio which is as per IS10262-2009
So, W/C ratio = 0.57
From table 5 of is 456-2000, maximum free water –cement ratio for moderate exposure is
W/c ratio = 0.60
Final water cement ration will be taken as minimum of the above two values,
Therefore, W/C ratio = 0.57

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STEP 3: AIR CONTENT CALCULATION
Nominal maximum size of aggregate taken is = 20mm
Nominal maximum size of aggregate Air content (% of volume of concrete)
10mm 5%
20mm 2%
40mm 1%
So, from the table entrapped air content in % of volume of concrete = 2%
STEP 4: WATER CONTENT CALCULATION
For nominal maximum size of aggregate of 20mm, the required water content is selected form
the table and it is
W = 186 liters
Nominal maximum size of aggregate Maximum water content
10mm 208
20mm 186
40mm 165
The aggregate nominal maximum size is 20mm and they belong to zone 2. So, Adjustment for
compacting factor is to be applied.
Therefore, water content = 186 + (186 x 3/100) = 191.6 lit / m3 of concrete.
STEP 5: CEMENT CONTENT CALCULATION
From step 2, Water cement ratio = W/C = 0.57
From step 4, Water content W = 191.6 liters = 191.6kg
191.6 / C = 0.57
Finally, C = 336.14 Kg / m3 of concrete

22
But from table 5 of IS456-2000, Minimum cement content required for moderate exposure
condition for M15 grade concrete is = 240 Kg/m3 of concrete.
Greater of above two values will be the cement content.
Hence, C = 336.14Kg
STEP 6: AGGREGATE RATIO FOR CONCRETE
From the table, ratio of volume of coarse aggregate to volume of total aggregate, for 20mm
nominal maximum size aggregate and zone-2 fine aggregate is
Therefore, P = 0.62
STEP 7: AGGREGATE CONTENT CALCULATION
Volume of concrete (with entrapped air) = 1 m3
From step 3, Entrapped air % = 2% = 0.02
Therefore, volume of concrete (without air content) = 1-0.02 = 0.98m3
Fine aggregate content F.A is determined from below formula,
V = [W + C/Gc + (1/ (1-P) X (F.A)/Gf)] x 1/1000
0.98 = [191.6 + 336.14/3.15 + (1/ (1-0.62) X (F.A)/2.6)] x 1/1000
Therefore, amount of fine aggregate F.A = 673.52kg
Similarly, Coarse aggregate content C.A is derived from
Therefore, amount of coarse aggregate C.A = 1120kg
STEP 8: FINAL MIX PROPORTIONS OF INGREDIENTS
W/C ratio = 0.57 ,Cement quantity = 336.14Kg = 337kg
Fine aggregate quantity = 673.52kg = 674kg
Coarse aggregate Quantity = 1120 kg
Mix proportion = Cement : F.A : C.A = 1 : 2 : 3.3

23
8. REGULAR GRADES OF CONCRETE AND THEIR USES
Regular grades of concrete are M15, M20, M25 etc. For plain cement concrete works, generally
M15 is used. For reinforced concrete construction minimum M20 grade of concrete are used.
CONCRETE
GRADE
MIX
RATIO
COMPRESSIVE STRENGTH
MPA
(N/MM2)
PSI
NORMAL GRADE OF CONCRETE
M5 1 : 5 : 10 5 MPa 725 psi
M7.5 1 : 4 : 8 7.5 MPa 1087 psi
M10 1 : 3 : 6 10 MPa 1450 psi
M15 1 : 2 : 4 15 MPa 2175 psi
M20
1 : 1.5 :
3
20 MPa 2900 psi
STANDARD GRADE OF CONCRETE
M25 1 : 1 : 2 25 MPa 3625 psi
M30
Design
Mix
30 MPa 4350 psi
M35
Design
Mix
35 MPa 5075 psi
M40
Design
Mix
40 MPa 5800 psi
M45
Design
Mix
45 MPa 6525 psi

24
HIGH STRENGTH CONCRETE GRADES
M50
Design
Mix
50 MPa 7250 psi
M55
Design
Mix
55 MPa 7975 psi
M60
Design
Mix
60 MPa 8700 psi
M65
Design
Mix
65 MPa 9425 psi
M70
Design
Mix
70 MPa 10150 psi

25
8.1 RATIOS
8.1.1 FIRST RATIO
8.1.2 SECOND RATIO
8.1.3 CONVENTIONAL
CEMENT
1cft=42.64kg
SAND
1cft=43.30kg
FLYASH
1cft=41.32kg
CHIPS
1cft=45.30kg
RUBBER
SCRAP
1cft=42.64kg
COCONUT
SHELL
1cft=38.36kg
(2+2)
= 4
0.83 cft
(4+4)
= 8
1.69 cft
(1+1)
= 2
0.40 cft
(8+8)
= 16
5.33 cft
4
0.83 cft
2
0.38 cft
CEMENT SAND FLYASH CHIPS RUBBER
SCRAP
COCONUT
SHELL
(2+2)
= 4
0.83 cft
(4+4)
= 8
1.69 cft
(1+1)
= 2
0.40 cft
(8+8)
= 16
5.33 cft
6
1.25 cft
2
0.38 cft
CEMENT SAND FLYASH CHIPS RUBBER
SCRAP
COCONUT
SHELL
(2+2)
= 4
0.83 cft
(4+4)
= 8
1.69 cft
(1+1)
= 2
0.40 cft
(8+8)
= 16
5.33 cft
0 0

26
8.2 STRENGTH ATTAINED
8.3 WATER ABSORPTION TEST
Concrete can be converted into precast masonry units such as Hollow and Solid normal and light
weight concrete blocks of suitable size to be used for load and non-load bearing units for
wallings. Use of such concrete blocks are more appropriate in region where soil bricks are costly,
poor in strength and are not available. Depending upon the structural requirements of masonry
unit, concrete mixes can be designed using ingredients available locally or if not found suitable
then with in the most economical distance. The concrete mix used for normal hollow and solid
blocks shall not be richer than one part by volume of cement to 6 parts by volume of combined
room dry aggregates before mixing.
Concrete blocks for normal work used in masonry when reinforced is used shall not be leaner
than 1 part cement to 8 parts room dry sand by volume. The mixes are designed with the
available materials to give overall economy and the required properties of the products. The
hollow load bearing concrete blocks of the standard size 400 x 200 x 200 mm will weight
between 17 and 26 kg (1063 to 1625 kg/m3) when made with normal weight aggregates. Normal
weight blocks are made with cement, sand, gravel, crushed stone and air-cooled slag. The
grading for sand used in Hollow concrete block shall be as given below:
DAYS STRENGTH ATTAINED
01ST DAY 16%
03RD DAY 40%
07TH DAY 65%
14TH DAY 90%
28TH DAY 99%

27
I.S. Sieve Size Percentage Passing
4.75 mm 98-100
2.36 mm 80-100
1.18 mm 60-80
600 Micron 40-65
300 Micron 10-40
150 Micron 0-10
The aggregates for solid blocks shall be sand as per IS : 383-1970 and well graded aggregate of
suitable maximum size as per the dimensions of the block. The mixes are properly designed as
per standard practice. Concrete admixtures may be used in both Hollow and Solid concrete
blocks.
8.4 SPECIMEN
20 full size units shall be measured for length, width and height. Cored units shall also be
measured for minimum thickness of face, shells and webs. From these 3 blocks are to be tested
for block density, 8 blocks for compressive strength, 3 blocks for water absorption and 3 blocks
for drying shrinkage and moisture movement.
8.5 DETERMINATION OF BLOCK DENSITY
Three blocks shall be dried to constant mass in a suitable oven heated to approximately 100OC.
After cooling the blocks to room temperature, the dimensions of each block shall be measured in
centimeters to the nearest millimeter and the overall volume computed in cubic centimeters. The
blocks shall then be weighted in kilograms to the nearest 10 gm. The density of each block
calculated as follows:
Density in kg/m3 = Mass of block in kg/Mass of block in cm2 X 106
8.6 DETERMINATION OF WATER ABSORPTION
Three full size blocks shall be completely immersed in clean water at room temperature for 24
hours. The blocks shall then be removed from the water and allowed to drain for one minute by
placing them on a 10 mm or coarser wire mesh, visible surface water being removed with a damp
cloth, the saturated and surface dry blocks immediately weighed. After weighing all blocks shall

28
be dried in a ventilated oven at 100 to 1150C for not less than 24 hours and until two successive
weighing at intervals of 2 hours show an increment of loss not greater than 0.2 percent of the last
previously determined mass of the specimen. The water absorption calculates as given below:
Absorption, percent =(A-B)/B * 100
Where,
A = wet mass of unit in kg.
B = dry mass of unit in kg.

29
9. TESTING BLOCKS FOR COMPRESSIVE STRENGTH
9.1 COMPRESSION TESTING MACHINE (CTM)
The compression testing machine should be as per IS : 516-1959 and I.S : 14858-2000. The load
capacity, platens sizes, vertical space between platens and horizontal space between machine
columns shall be as per the requirements of the specimens to be tested.
However, IS : 2185 (pert-I) – 1979 specified that when the bearing area of the steel blocks is not
sufficient to cover the bearings area of the blocks, steel bearing plates shall be placed between
the bearing blocks and the capped specimen after the centroid of the masonry bearing surface has
been aligned with the centre of thrust of the bearing blocks. It is desirable that the bearing faces
of blocks and plates used for compression testing of concrete masonry have hardness of not less
than 60 (HRC).
When steel plates are employed between the steel bearing blocks and the masonry specimen, the
plates shall have thickness equal to at least one-third of the distance from the edge of the bearing
block to the most distant corner of the specimen. In no case shall the plate thickness be less than
12 mm.
To increasing the compressive strength of concrete, we must increase cement and decrease water
quantity. For example, M15 grade of concrete when we use50 kg of cement,480 kg aggregates
and32 liters water we get15N/sq.mm compressive strength after28 days by15 cm. cube test. But
for M20 grade of concrete when we use50 kg of cement,360 kg aggregates and30 liters water we
get20N/sq.mm compressive strength after28 days by15 cm. cube test. But remember here,
volume of M20 concrete is less then volume of M15 concrete. So if we increase the compressive
strength of concrete,then we have to increase the quantity of cement and water.

30
9.2 COMPRESSIVE STRENGTH
M15 (DAYS) CONVENTIONAL RATIO 1 (4 BOND
OF RUBBER)
RATIO 2 (6 BOND
OF RUBBER)
AT 7th DAY
960 KN
960*103/(400*200)
= 12 N/mm2
1030 KN
1030*103/(400*200)
= 12.875 N/mm2
990 KN
990*103/(400*200)
= 12.375 N/mm2
AT 14th DAY
1090 KN
1090*103/(400*200)
= 13.625 N/mm2
1160 KN
1160*103/(400*200)
= 14.5 N/mm2
1110 KN
1110*103/(400*200)
= 13.875 N/mm2
AT 21st DAY
1210 KN
1210*103/(400*200)
= 15.125 N/mm2
1270 KN
1270*103/(400*200)
= 15.875 N/mm2
1220 KN
1220*103/(400*200)
= 15.25 N/mm2
AT 28th DAY
1330 KN
1330*103/(400*200)
= 16.625 N/mm2
1460 KN
1460*103/(400*200)
= 18.25 N/mm2
1390 KN
1350*103/(400*200)
= 17.375 N/mm2
Thickness of bearing plates has a significant effect on the tested compressive strength of
masonry units when the bearing area of the platen is not sufficient to cover the area of the
specimen. Tested compressive strength will typically increase with increased plate thickness and
with reduce distance to the further corner of the specimen. Accordingly the CTM platens shall
have the required dimensions with respect to the specimens to be tested on it.

31
9.2.1 COMPRESSIVE STRENGTH VALUE CHART
9.3 TEST SPECIMENS
Eight full size units shall be tested with in 72 hours after delivery to the laboratory, during which
time they shall be stored continuously in normal room air.
For the purpose of acceptance, age of testing the specimens shall be 28 days. The age shall be
reckoned from the time of the addition of water to the dry ingredients.
9.4 CAPPING TEST SPECIMENS
The bearing surfaces of units shall be capped by gypsem. The gypsem and water paste shall be
spread evenly on a non-absorbent surface that has been lightly coated with oil. The surface of the
unit to be capped shall be brought into contact with the capping paste. The average thickness of
the cap shall be not more than 3 mm. The caps shall be aged for at least 2 hours before the
specimens are tested.
9.4.1 ADVANTAGES
 It increases the speed of construction
 It promotes green constuction
 Coconut shells are more resistant towards crushing,impact and abrasion
 Reduction in density of concrete
 Improves the ductility of the mix
 Increases the tensile strength
0
2
4
6
8
10
12
14
16
18
20
RATIO 1 RATIO 2 CONVENTIONAL
AT 7th DAY
AT 14th DAY
AT 21st DAY
AT 28th DAY

32
10. CONCLUSION
Broad exploration was completed on control concrete with ordinary total and CS incomplete
percentile supplanting on total for cement with 25 - half coarse total supplanting were set up with
consistent water – folio proportion of 0.45. For all blends, workability, thickness, water
assimilation, compressive quality flexural quality and rigidity were resolved at 7, 14 and 28 days.
The accompanying conclusions can be gotten from the present examination: The outcomes
demonstrated a relentless decrease in the workability. The 0.45, water bond proportion which
was kept consistent all through the blend made the workability lower. The workability really
diminishes as there is an expansion in the measure of CS added to the blend. Because of the
nonappearance of super plasticizers the workability of the solid was on the lower side.
The water ingestion tests demonstrated that the rate water retention increments with expansion in
the rate supplanting level of coarse total with CS. half of CS substitution demonstrates the most
noteworthy water retention took after by 25% and in conclusion half of CS. The compressive
qualities of CS 1concrete were observed to be lower than ordinary cement by 5–55% following 7
days, 9-half following 14 days and by 12–52% following 28 days, contingent upon the curing
environment. Their qualities were inside the typical extent for auxiliary lightweight cement.
Flexural quality of solid examples diminishes with expansion in the rate supplantings of coarse
total with CS for all curing days. 25% CS level was distinguished as the ideal substitution rate
since its shows the most noteworthy flexural quality by supplanting a coconut shell by 25% as
coarse total are helpful and all test outcome are effective. Waste tire rubber powder is used in a
variety of civil and non-civil engineering applications.
Some properties of rubber powder resulting from crushing of light vehicles waste tires with no
steel fiber have been determined in this work: the particle size, the density, the chemical
composition as well as the cohesion and friction angle by direct shear test. Rubber powder,
crushed mechanically in ambient temperature, showed has a very low density of about 0.83,
cohesion varied from 6.5 to 50 kPa. Friction angle varied from 8 to 25° according to the average
size rubber particle. Using the results from this study along with previous results from other
studies, cubic regressions is proposed. Cohesion as well as friction angle versus particle size
using cubic model give respectively for the coefficient of determination values of 72.3 and
80.1%.

33
REFERENCE
 ISO289 Rubbers and rubber mixtures, Assessment of viscosity and curing on viscosity-
meter Mooney.
 ISO 37 Rubber or thermoplastic elastomers, assessment of tensile properties.
 ISO 7619 Rubber, plastics and ebonite, assessment of hardness by inserting of the
hardness tester point (Shore hardness).
 ISO 4662 Rubber, assessment of rubber transition flexibility.
 ISO 34-1 Rubber, assessment of structure strength.
 SO 4649 Rubber, assessment of abrasion resistance on apparatus with rotating drum.
 ISO 188 Rubber, assessment method of accelerated thermal ageing in the air.
 Topcu U B 1995 The Properties of Rubberized Concrete Cement and Concrete Research.
 pp 304-10.
 Benazzouk A and Queneudec M 2002 Durability of Cement-Rubber Composites under
Freeze.
 Thaw Cycles Proceedings of International congress of Sustainable Concrete Construction
 (Dundee) pp 355-62.
 Fissuration Rencontres Universitaires de Genie Civil (Des Mortiers).

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