Abstract
Waste rubber tyres nowadays are a big headache for the authorities. The rubber tyres are non biodegradable due to which their disposal is not possible and also it is polluting substance. Many ways are invented for the disposal for waste rubber tyre .One of that attempt has done in construction technology. From last two decades ,this research on use of waste rubber tyre has been started. It is a big advantage for concrete that by the use of the chipped rubber the properties like flexibility, lightweight, elasticity, energy absorption and sound properties are adopted. In this study the concrete utilizing waste tyre rubber has been investigated. Recycled waste tyre rubber has been used in this study to replace the coarse aggregate by weight using different percentages. And the properties like compressive strength, split tensile strength are compared between the rubberized concrete and the normal concrete. The rubber percentage will replaced by 0%,10%,20%,30% in the concrete mix of grade M20 and M25.
Chapter 1 Introduction
1.1 Organization Profile
1.2. Project Detail
1.2.1 Project Definition
“Rubber concrete”
In this modern world, the use of tyre are extensively high .Also to recycle the rubber waste is very much impossible and dangerous to environment, as it produces dangerous poisonous fumes which adversely affect the environment. So the environment engineers are concerned regarding the rubber waste. As the waste becomes on increasing, different companies try to use tyre in building construction. The clever use of rubber waste can result into low cost buildings and effective disposal of rubber waste. It is estimated that 11% of tyres are exported and 27% are sent to land filling or dumped. The 4% of the tyre waste are used in construction. So this problem deals with identifying the problem and then giving suitable solutions to overcome them and to reduce the rubber waste.
1.2.2 Use of waste tyre
Rubber wastes is used in floor mats , belts , gaskets , shoe sales , dock bumper , seal ,muffler hangers , shims and washers. It is also used as a fire ingredient in cement kilns and brick kiln. Also some tyres are used as a boat bumper , highway crash barriers . However by burning tyres in environment it is harmful to the nature so the use of rubber is banned by government.
It has been observed that the rubber concrete is used when toughness is more desirable than strength. It can be used as bridge barriers and road foundation .The desirable properties which can be used for future investigations on rubber concrete. In this project an attempt has been made to identify the various properties of rubber concrete.
1.3 Purpose
The purpose of this project is to reduce the rubber waste produced. Reduced rubber wastes will also stop the environment from degradation.
1.4 Scope
The scope of this project is to analyze the different properties of traditional concrete and rubber concrete. Tests on the concrete will be carried out on both the traditional and rubber concrete and the results will be compared thoroughly.
1.5 Objective
The objective is to find properties of rubber concrete and analyze its properties. The properties like compressive strength, tensile strength and split tensile strength are studied; also the comparison is shown by graphical manner to understand it better. The objective of this project is to find the solution of rubber waste and to find a way to use the rubber effectively to benefit the society.
1.6 Materials Used and Testing
The basic materials used for mixing of concrete are as follows:
• Cement,
• Sand,
• Aggregate,
• Chipped Rubber,
• Silica fume
Cement
The cement used for the project is ordinary Portland cement grade 53. Cement is Ultra tech cement with provides high durability for concrete structures. Cement is according to BIS specification IS:12269-1987 with a designed strength of 28 days.
Fineness test
The fineness test of cement has an important bearing on the rate of hydration and hence on the rate of gain on strength and also on rate of evolution of heat. The smaller the particle size, the greater the surface area-to volume ratio, and thus the more area available for water-cement interaction per unit volume. The effects of greater fineness on strength are generally seen during the first seven days. For a rapid development of strength a high fineness is necessary.
We got 1.2% weight of residue of cement left from the 90 micron sieve.
Standard Consistency Test
The aim of this test is to determine the standard consistency of cement. Standard consistency means consistency which permits the vicat’s plunger of 10 mm diameter to penetrate to a point 5mm to 7mm from the bottom of vicat’s mould with gauging time 3 to 5 minutes. It is expressed as amount of water as a percentage by weight of dry cement. Gauge time is period observed from the time water is added to cement for making cement paste till commencing the filling of mould of vicat’s apparatus in this test.
Observation no 1 2 3
Weight of water added W2 gm 108 132 140
Penetration of plumber bottom in mm 18 10 6
% by weight=W2/W1 27 33 35
Intial and final setting time of cement
The aim of this test is initial and final setting time of cement. The test block is filled with 400 gm of cement and fill the vicat’s mould.
Determination of initial setting time
Place the mould together with the non porous plate under the rod bearing the intial setting time needle. Adjust the needle so that so that it touches the surface of test block .release needle quickly allowing it to sink in this cement paste in this mould. The time shown by stop watch is 30 min.
Determination of final setting time
Replace the needle of vicat’s apparatus by the needle with an annular attachment. Apply the needle gently to the surface of test block .Repeat this procedure , until the needle makes an impression while the attachment fails to do so. The time taken by needle is 600 min.
Compressive strength of cement
The aim of this test is to determine the compressive strength .compressive strength of cement indicates the compressive strength of cement mortar cubes of 1:3 proportion, using standers sand as specified by IS: 650(1996) as fine aggregate, tested under compression, many others properties of mortar/concrete are related to compressive strength of cement, because cement is used in structure in form of mortar or concrete.
Observation no 1
Crushing period(Days) 3
Load at failure(KN) 7
Compressive strength N/mm2 1.43
Sand (Fine aggregate)
The locally available river sand from banas- river, Gujarat, India, is used as fine aggregate in the concrete design mix. The specific gravity, water absorption and fineness modulus are 2.61, 0.82% and 2.78 respectively. Sand is of Zone-3 as per IS: 383-1970. The physical properties of aggregate were considered according IS: 2386(1963).
Aggregate most of which pass through 4.75 mm IS sieve is known as fine aggregate. Fine aggregate shall consists of natural sand, crushed stone sand, crushed gravel sand stone dust or arable dust, fly ash and broken brick (burnt clay).
Sieve Passing wt. Retained wt. % passing by wt.
10 mm 0 0 100
4.75 mm 0.0784 2.46 97.54
2.36 mm 0.057 1.9 95.64
1.18 mm 0.140 4.67 90.67
600 micron 0.136 4.53 86.44
300 micron 2.209 73.63 12.81
150 micron 0.181 6.03 6.78
So by grading limits of fine aggregate from IS :383-1970 we obtained the sand as zone 3.
Coarse aggregate
Coarse aggregate shall be of hard broken stone of granite or similar stone. It shall be hard, strong, durable and dense. It should be free from soft friable, thin, flat, elongated, flaky particle. It should be free from dust, dirt, vegetable and organic matter unless specially mentioned. The size of coarse aggregate shall be 20mm graded down and shall be retained in a 5mm square mesh sieve.
Impact test
The aim of this test is to determine the impact value of given aggregate as per I.S 2386 Part 4.toughness is the property of material to easiest impact .Due to moving parts the aggregate are subjected to pounding action or impact and there is possibility of stones.
The aggregate impact value indicates a relative measure of the resistance of aggregate to a sudden shock or an impact, which aggregate differs from its resistance to a slope compressive load in crushing test.
The maximum allowable aggregate impact value for water bound macadam, sub base coarse 50% where as cement concrete used in base coarse as 45 % .WBM base coarse with bitumen surface in should be 40% . Bituminous Macadam base course should have A.I.V. of 35%.All the surface courses should possess an A.I.V below 30%.
Sr no Details of Sample Result
1 Total weight of aggregate sample=W1 321
2 Weight of aggregate passing 2.36 mm sieve=W2 31
3 Weight of aggregate retained 2.36 mm sieve=W3 291
4 (W1-W2+W3) 581
5 Aggregate impact Value=(W2/W1)*100% 9.65
Fineness modulus of aggregate
This test is used to determine fineness modulus of aggregate. Sieve analysis is the operation of dividing sample of aggregates into various functions .Each consisting of particles of same size. The sieve analysis is conducted to determine the particle size distribution in the sample of aggregates. This is known as graduation. The aggregates generally used for making concrete are of maximum 50 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 60 , 150 . The aggregate fractions from 80 mm to 4.75 mm are termed as coarse aggregates. Those fractions from 4.75 mm to 150 are termed as fine aggregates.
Sieve size Coarse aggregate Fine aggregate
Wt retained
(gm) % of wt retained Cumulative % retained % passing Wt retained % wt retained Cumulative % retained % passing
40mm 1238 24.76 24.76 75.24 – – – –
20mm 419 8.38 33.14 66.86 – – – –
10mm 2824 56.48 89.62 10.38 – – – –
4.75mm – – – – 52 62.6 2.6
2.36mm – – – – 74 3.7 6.3 93.7
1.18mm – – – – 121 6.05 12.35 87.65
600 micron – – – – 153 7.65 20 80
300 micron – – – – 1363 68.15 88.25 11.85
150 micron – – – – 105 5.25 93.4 6.60
75 micron – – – – 110 5.50 98.6 1.1
F.M=2.475 F.M=3.217
F.M=sum of % cumulative relative on 40mm to 75 micron/100
=569.22/100
=5.69
Specific Gravity of Aggregate
This test is used to determine specific gravity of aggregate. Specific gravity of aggregates is made use of in design calculation of concrete mines with the specific gravity of each constituent known, its weight can be correlated into solid volume and hence a theoretical yield of concrete per unit volume can be calculated. Sp. Gravity of the aggregate is also required in calculating the compacting factor in connection with the workability measurements. Similarly Sp. Gravity of aggregate is required to be considered we deal with light weight and heavy weight concrete. Average specific gravity of the rocks varies from
Sp. gravity=D/C-(A-B)
The specific gravity obtained is 3.15.
Rubber
The waste tyre rubber is purchased from local market in gota (Ahmedabad). The size of the rubber is taken as 20 mm. The rubber has rough surface so as to allow the good bonding with concrete.
Properties of Rubber are
Compacted density 2.3 to 4.8Kn/mm2
Unit weight 1/3 of soil
Durability Non biodegradable
Specific gravity 1.14 to 1.27
Unit weight Half the unit weight
Silica fume
Silica fume or micro silica collected from moon trader supplier of pozzolanic material located in Madurai. Net weight of bag contains 50kg of powder. Silica fume also referred as micro silica or condensed silica fume is another material that is used as an artificial pozzolanic admixture. It is a product resulting from reduction of high purity quartz with coal in an electric arc furnace in the manufacture of silicon or ferrosilicon alloy. Specific gravity of silica fume is 2.2.
CEMENT :
SPECIFIC GRAVITY : 3.15
GRADE OF CEMENT :53
INITIAL SETTING TIME : 60 MIN
FINAL SETTING TIME : 5 HRS
FINE AGGREGATE
SPECIFIC GRAVITY :2.61
WATER ABSORPTION :0.82
GRADING OF ZONE : ZONE III
COARSE AGGREGATE
SPECIFIC GRAVITY :2.65
WATER ABSORPTION: 0.2
1.7Literature review
Sr no Title
Publishing year
Author/Publisher
Content
1) Study of rubber aggregates in concrete an experimental investigation
December 2016
MOHAMMED MUDABHEER AHMED SIDDIQUI1 (Department Of Civil Engineering, Vits Engineering College/ JNTU Hyderabad, Telengana , India)
A study has been done on normal M20 grade concrete with aggregate in normal proportion and partially replaced aggregate with crumb rubber by an amount of 0%,5%,15%,20%.
2) effect on compressive strength of concrete
by using waste rubber
as partial replacement of fine aggregate
March 2016
ANIRUDDH, MR. ABHISHEK KUMAR, MOHD. AFAQUE KHAN M20 concrete mix has used in the study and replacement of 5,10,15,20,25%.compressive strength decreases with increase in rubber proportion, flexural strength decreases, slump value increases up to 1.08 after that it decreases, stress strain going to vary with increase in the proportion.
3) Experimental study on concrete by partial
replacement of fine aggregate with crumb
rubber
2015
A MANSOOR ALI
M.E., Structural Engineering student,
SKPEngineering College, Tiruvannamalai.
A.SARAVANAN
HOD Civil Engineering
SKPEngineering College, Tiruvannamalai.
M25 concrete is been used with proportion of 0%,5%,10%,15%,20%.Properties like compressive strength, durability test, flexural strength have been compared and final observations are taken as result.
4) An experimental study on strength of concrete containing crumb rubber with alccofine
2015
ATHIRA PAVITHRAN, T.ASHOK KUMAR, MINU ANNA JOHNY In order to fulfill the insufficient of aggregates, have to use some alternative materials like Alccofine, Crumb Rubber etc. which are recycled or waste materials. In this study concrete mix designs are prepared by using IS method (for M30 grade of concrete).
5) Using tyres wastes as aggregates in concrete to form rubcrete – mix for engineering applications 2014
ER. YOGENDER ANTIL M30 concrete mix has used. Aggregate is replaced with rubber by (5%,10%,15%,20%)volume, properties like compressive strength, flexural strength, spit tensile strength, stress strain behavior are observed and result is taken.
6) Rubberized concrete made with crumb rubber
2014
YOGENDER ANTIL, ER. VIVEK VERMA, ER. BHUPINDER SINGH
In the study M30 mix concrete has used with (5,10,15,20,25%) proportion of rubber by volume. compressive strength and slump behavior has observed. Results taken as conclusion
7) Enhancement of mechanical properties of rubber crumb
concrete using pretreated rubber crumbs and alccofine
2014
KRUNAL N. PATEL,
PROF. M.A.JAMNU
A total number of 21 numbers of mixes has casted with 0% of replacement of rubber crumbs with fine aggregate as control then followed by 5%, 10%, 20% and 30% separately for each replacement of cement with Alccofine (GGBS) percentage of 4%, 6%, 8% and 10%. All of the mixes are tasted with the
compressive strength test, split tensile test and flexural strength test.
8) Concrete made for energy conservation using recycled rubber aggregates September. 2013
MOAYYAD AL-NASRA, ZELJKO TORBICA
The focus was on 0 percent, 10 percent and 20 percent of rubber aggregates replacement of the mineral aggregates. The mix design remained the same but portion of the mineral aggregates were replaced by rubber aggregates at a rate of 0 percent to 20percent.Comparitive study in compressive strength,split tensile strength
9) Laboratory evaluation of usage of waste tyre rubber in bituminous concrete September 2013
MISS. MANE PRIYANKA ARUN,
MR. PETKAR DEEPAK GANESH,
MR. BHOSALE S.M.
60/70 grade of bitumen has used with varying proportion of crumb rubber (5,10,15,20,30,40%)in total volume. Properties like marshall stability,flow value, values of air voids, values of voids filled with bitumen are observe and final results taken as conclusion.
10) Recycled tyres as coarse aggregate
in concrete pavement mixtures
July 2013
RUI LIU,
University of Colorado Denver
Department of Civil Engineering
College of Engineering and Applied Science
The coarse aggregate
Component of the mixture was replaced in 100%, 50%, 30%, 20%, and 10% by volume using tyre chips. The fresh
concrete properties, compressive strength, flexural strength, splitting strength, permeability, and freeze/thaw durability
Were tested in the lab to evaluate the potential of including tyre chips in concrete paving mixes.
11) Effects of recycled tyres rubber aggregates on the characteristics of cement concrete 2012
ZEINEDDINE BOUDAOUD
,MILOUD BEDDAR1
In the study M15 mix concrete has used with (5,10,15,20,25,30%)proportion of rubber by volume. compressive strength ,flexural strength, and shrinkage behavior has observed. Results taken as conclusion.
12) Discarded tyre rubber as concrete aggregate:
A possible outlet for used tyres
September 2010 M. MAVROULIDOU
J. FIGUEIREDO
Department of Urban Engineering,
London South Bank University,
103 Borough Road, London, SE1 0AA, UK
A study has been done on normal M20 grade concrete with aggregate in normal proportion and partially replaced aggregate with crumb rubber by an amount of 0%,10%,20%,30%.Comparision between workability, Density, Compressive strength, split tensile strength, flexural strength have been done and taken as a result.
Chapter 2: Design: Analysis, Design Methodology and Implementation Strategy
2.1 AEIOU Summary Framework:
This sheet gives all the information about project related to surrounding the work, peoples interacted, instruments used, and people related to the project.
2.2 Ideation canvas:
This sheet gives the idea about the people related, activities done, location of the work, equipments used during performing the project.
2.3 Ideation funnel Canvas:
This sheet gives the information about the challenges, peoples, locations and revenue model if there something productive is there in the project.
2.4 Observation Matrix
The sheet gives the process of specifying the problem by continuous evaluation of major problem to minor problem. At the end we found the problem related to our project.
2.5 Product Development:
This sheet gives the overall process of product development. It gives the information about people related, purpose, product experience, product features, and customer revalidation.
2.6 BMC model
BUSINESS MODEL CANVAS
CUSTOMER SEGMENTS
• CIVIL ENGINEERS, CONTRACTORS, Civilians, WASTE RUBBER DEALER etc who connected to the products are our customers.
VALUE PROPOSITIONS
• Rubberized concrete is an important step towards the utilization of waste rubber.
• As it has the moderate strength it can be used in non load bearing structures, RCC roads, parking plots.
• Also it is cost efficient as the admixtures are of the negligible cost.
CHANNELS
• These are the channels through which we can spread awareness of this product
• COMMERCIAL ADVERTISEMENT
• MARKET AWARENESS
• CAMPAIGNING
• POLLUTION AWARENESS
CUSTOMER RELATIONSHIP
• TRUST WORTHY
• COMMITMENT
• WORK SPACE
• WORK ENVIRONMENT
REVENUE STREAMS
CUSTOMER SEGMENT DEVELOPEMENT
KEY ACTIVITIES
• Material test are firstly done for preparation of design.
• Concrete mix design is calculated and proportion are decided.
• Cubes are casted as per decided proportion of the design.
• Compression strength test and split tensile strength are tested at 7 days and 28 days.
KEY RESOURCES
• CEMENT
• AGGREGATE
• SAND
• WASTE TYRE RUBBER
• SILICA FUME
KEY PARTNERSHIPS
• Civil Engineer, Contactors and customers can use this concrete in aesthetically sound, on load bearing structures, light structures and RCC roads.
• Developer can do further investigation on the product and can improve its efficiency.
COST STRUCTURE
• CEMENT COST
• AGGREGATE COST
• RUBBER COST
• SILICA FUME COST
• SAND COST
Chapter: 3
About The project
3.1 Project Specification Requirement
The management of waste rubber tyres is very difficult for government authorities as is non biodegradable for long time. However it can be recycled and can be used in many applications. such as fuel for cement kiln, as feedstock for making carbon black ,and as artificial reefs in marine environment. It has also been used as a playground matt, erosion control, highway crash barriers, guard rail posts, noise barriers, and in asphalt pavement mixtures. From past two decades, research had been performed to study the availability of using waste tyre rubber in concrete mixes. Recycled waste tyre rubber is a promising material in the construction industry due to its lightweight, elasticity, energy absorption, sound and heat insulating properties. In this study the concrete utilizing waster tyre rubber has been investigated. Recycled waste tyre rubber has been used in this study to replace the coarse aggregate by weight using different percentages.
3.2 Project study
3.2.1. Concrete Terminologies
Concrete grade: Concrete grades are denoted by M10, M20, M30 according to their compressive strength. The “M” denotes Mix design of concrete followed by the compressive strength number in N/mm2.
Compressive strength: Compressive strength is the capacity of a material or structure to withstand loads tending to reduce size
Split tensile strength: A measure of the ability of material to resist a force that tends to pull it apart.
Concrete properties
Hardened Concrete Properties Compression test according to IS: 516(1959) is carried out on these cubes. The specimens were loaded at a constant strain rate until failure. The compressive strength is decreased with an increase in the percentage of the tyre rubber chips. The results of compressive strength of cubes for 7 days and 28 days are as follows.
Durability
Since rubber waste concrete has lower compressive strength than reference concrete it is expected that is behavior under fast mechanical degradation actions could also be lower. s. According to them the use of a 10% replacement is feasible for regions without harsh environmental conditions.
Density
The general density reduction was to be expected due to the low specific gravity of the rubber aggregates with respect to that of the natural aggregates. The reduction in density can be a desirable feature in a number of application, including architectural application such as nailing concrete, false facades, stone backing and interior construction as well as precast concrete, light weight hollow and solid blocks, slabs etc.
Effect of texture of rubber particle surface
Various studies show that the rougher the rubber particles used in concrete mixtures the better the bonding they develop with the surrounding matrix and, therefore, the higher the compressive strength of rubcrete concrete may be obtained by improving the bond between rubber particles and the surrounding cement paste
3.2.2. Methodology
For preparation the recycled chipped rubber concrete specimens, fine aggregates were replaced by waste materials of chipped rubber in several percentages (0%, 10%, 20%, and 30%) in separate concrete mixes. The sand used is cleaned from all inorganic impurities and the sand, which passed through 2.36 mm sieve and retained on 150micron had been used. For each mix, cubes of 150 X 150 X150 mm, cylinders of 150 mm diameter by 300 mm height, and small beams of 100X 100 X 500 mm were prepared. All specimens were fabricated and then cured in water for 28 days in accordance with Indian Standard 10262. After 24 hours of casting cubes, beams and cylinders were taken out from the mould and then submerged in water tank for curing.
After the curing the cubes will be pass through the following test :
• COMPRESSIVE STRENGTH OF CONCRETE
• SPLIT TENSILE STRENGTH
Flow chart
3.2.3 EXPERIMENTS
1) COMPRESSIVE STRENGTH TEST :
1. One of the important properties of concrete is its strength in compression. The strength in compression has a definite relationship with all the other properties of concrete, these properties are improved with the improvement in the compressive strength, hence the importance of the test.
2. The strength that may be developed by workable, properly placed mixture of cement, aggregate and water is influenced by.
a. Ratio of cement to mixing water.
b. Ratio of cement to aggregate.
c. Grading, surface texture, shape strength and stiffness of aggregate particle.
d. Maximum size of aggregate.
2) SPLIT TENSILE STRENGTH TEST :
The test is carried out by placing a cylindrical specimen horizontally between loading surface of compressive testing machine and load is applied until failure of the cylinder along the vertical diameter takes place. The figure shows the test specimen and the stress pattern in the cylinder respectively. When the load is applied along the generation an element an element on the vertical diameter of the cylinder is subjected to vertical compressive stress of
2P/𝜋𝐿𝐷 = [𝐷2/ ((𝐷−𝑟)) – 1]
Where,
P = Compressive load on cylinder L = Length of cylinder
D = Diameter
r & (D-r) are the diameter of the elements from the two loads respectively.
Table 3.1 project planning table
July-August Project Definition, Literature Review, project study
September-October Concrete mix (0%)
November-December Concrete mix (10%,20%)
January-February Concrete mix (30%),data analysis and evaluation
March-April Conclusion , Recommendation and remedy measures and Project writing
Some pictures regarding the project
Chapter 4: WORK DETAILS
4.1 Concrete Mix Design
M20 Design
• STRENGTH AT 28 DAYS : 20 MPA
• MAX. SIZE OF AGGREGATE: 20 MM
• DEGREE OF WORKABILITY : 0.8
• DEGREE OF QUALITY CONTROL : GOOD
• TYPE OF EXPOSURE : MODERATE
• SP. GRAVITY OF CEMENT : 3.15
• SP. GRAVITY OF COARSE AGGREGATE : 2.65
• SP. GRAVITY OF FINE AGGREGATE : 2.61
• ZONING OF FINE AGGREGATE : ZONE 3
• WARER ABSORPTION :
– COARSE AGGREGATE : 0.2
– FINE AGGREGATE : 0.82
• TARGET MEAN STRENGTH:
20 + 1.65 × 4 = 26.6 MPA
• SELECTION OF W/C RATIO :
– 0.48
• SELECTION OF WATER AND SAND CONTENT (ADJUSTMENT) :
– CORRECTION S FOR ZONE : 186 ,33.5
– CORRECTION FOR WORKABILITY :186 ,33.5
– CORRECTION IN WATER CEMENT RATIO :186,31.5
– CORRECTION FOR ROUNDED AGGREGATE :186,31.5
– 186
– 31.5 %
• DETERMINATION OF CMENT CONTENT :
– W/C RATIO : 0.48
– WATER : 186 KG/M3
– CEMENT : 387.5 KG/M3
• DETERMINATION OF FINE AGGREGATE :
– 0.98 =[W +C/SC +1/P .fa /Sfa ] 1/1000
– 536.77 KG/M3
– DETERMINATION OF COARSE AGGREGATE :
– Ca = 1- P /P ×fa × Sca /Sfa
– 1185.15 KG/M3
M25 Design
• STRENGTH AT 28 DAYS : 25 MPA
• TARGETED MEAN STRENGTH :
– 25 +1.65 × 4 = 31.6 MPA
• SELECTION OF W/C RATIO :
– 0.45
• SELECTION OF WATER CONTENT :
– CORRECTION S FOR ZONE : 186 ,33.5
– CORRECTION FOR WORKABILITY :186 ,33.5
– CORRECTION IN WATER CEMENT RATIO :186,31.5
– CORRECTION FOR ROUNDED AGGREGATE :186,31.5
– 186 KG/M3
– 31. %
• DETERMINATION OF CEMENT CONTENT :
– 186/0.45 =413.33KG/M3
• DETERMINATION OF FINE AGGREGATE:
– 0.98 =[W +C/SC +1/P .fa /Sfa ] 1/1000
– 543.33KG/M3
• DETERMINATION OF COARSE AGGREGATE :
– Ca = 1- P /P ×fa × Sca /Sfa
– 1199.77 KG/M3
Proportion of mix design
M20 M20 M25 M25
WATER 192.97 0.49 190.13 0.46
CEMENT 387.5 1 413.33 1
F.A 536.77 1.38 543.33 1.3
C.A 1185.15 3.05 1199.77 2.9
4.2 Quantity of concrete material per cube
RUBBER PERCENTAGE (%) GRADE OF CONCRETE CEMENT (kg) F.A (kg) C.A (kg) RUBBER (kg) SILICA FUME (kg)
0 M20 1.33 1.862 4.123 0 0
M25 1.4 1.82 4.06 0 0
10 M20 1.33 1.76 3.71 0.412 0.093
M25 1.4 1.729 3.65 0.406 0.091
20 M20 1.33 1.76 3.298 0.824 0.093
M25 1.4 1.729 3.248 0.812 0.091
30 M20 1.33 1.76 2.886 1.236 0.093
M25 1.4 1.729 2.842 1.218 0.091
4.3 COMPRESSIVE STRENGTH VALUES
After the casting of cubes of M20 and M25 grades the compressive strength are taken at 7 days and 28 days for 0% , 10%, 20% and 30% of chipped rubber. The readings are shown below in tabular form, as the work is done by hand mixing there is slight deviation in readings as shown the table.
Table 4.1 Compressive strength data
GRADE OF CONCRETE RUBBER
(%) 7 days(KN/mm¬¬¬2) Avg 28 days(KN/mm2) Avg
1 2 3 1 2 3
M20 0 13.7 13.08 15.02 14.1 18.5 22.1 20.82 20.62
M25 0 15.6 18.5 17.2 17 24 27.5 26.8 26.02
M20 10 8.5 10.2 12.4 10.15 14.54 15.24 15.60 15.77
M25 10 11.85 12.64 12.12 12.24 16.24 18.58 23.38 19.87
M20 20 8.73 5.01 8.64 7.75 14.39 11.54 12.65 12.98
M25 20 7.29 10 10.3 9.35 18.65 16.84 17.82 16.34
M20 30 4.25 3.84 7.68 5.64 9.51 11.95 10.24 10.51
M25 30 5.59 5.87 7.92 6.8 14.64 12.94 13.55 13.32
Graphs regarding compression strength
4.4 SPLIT TENSILE STRENGTH
With casting of the cubes the cylinders are also casted of standard size simultaneously .The split tensile strength are taken at 7 days and 28 days for the 0% of chipped rubber .The readings are as shown in table below.
Table 4.2 SPLIT TENSILE STRENGTH DATA
GRADE OF CONCRETE RUBBER
(%) 7 days(KN/mm2)
28 days(KN/mm2)
M20 0 1.17 1.93
M25 0 1.411 2.44
M20 10 1.035 1.77
M25 10 1.24 2.226
M20 20 0.88 1.53
M25 20 1.065 1.94
M20 30 0.676 1.28
M25 30 0.816 1.625
Graphs Regarding Tensile Strength
Chapter: 5 Conclusion
5.1 Conclusion the project:
After performing these experiments of compressive strength and split tensile strength we got the estimated strength of the cube casted at 0% chipped rubber content. After adding 10% , 20% and 30% rubber the compressive strength and split tensile strength decreases thoroughly. Rubber concrete is more expensive than the normal concrete. The rubber concrete is used in the following:
• Rubcrete is used because of light unit weight is used as architectural purposes.
• It is recommended to use silica fume to increase the compressive strength of concrete.
• It is recommended to use rubber concrete in small structure like road curbs and partition walls.
• By using waste rubber, the waste rubber has been utilized properly.
References:
• A.M.Neville, concrete technology
• Eldin, N. N. and Senouci, A. B., 1993, “Observations on rubberized concrete behavior”, Cement, Concrete and Aggregates, 15, pp. 74-84.
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