Dr. Ambedkar Institute of Technology

VISVESVARAYA TECHNOLOGICALUNIVERSITY BELGAUM-590014

A Dissertation work On

“EXPERIMENTAL INVESTIGATION ON DEVELOPMENT OF LIGHT WEIGHT CONCRETE BY BLENDING WITH LECA AND CINDER” Submitted in partial fulfillment of the requirements for the award of degree Of

Master of Technology In STRUCTURALENGINEERING Submitted By

NAGASHREE B (USN: 1DA13CSE11) Under the Guidance of Dr. S.VIJAYA Professor Department of Civil Engineering, DR.AIT, Bangalore

For the Academic Year 2014-2015 Department of Civil Engineering

Dr. Ambedkar Institute of Technology Near JnanaBharathi Campus, Mallathahalli, Bangalore –560056.

ACKNOWLEDGEMENT The satisfaction that accompanies the successful completion of any task would be incomplete without mentioning the people who made it possible whose constant guidance and encouragements crowned my efforts with success. I take this opportunity to express my deepest gratitude and appreciation to all those who helped me directly or indirectly towards the successful completion of this project.

Firstly, I would like to thank Dr. T C MANJUNATH, Principal, Dr.AIT, Bengaluru, for all the facilities provided for carrying out this work successfully.

I also extend my sincere thanks to Dr. B SHIVA KUMARSWAMY, Head of the Department, Civil Engineering, for his constant support. I would like to express deepest gratitude and sincere thanks to my guide Dr. S.VIJAYA, Professor, Department of Civil Engineering, Dr.AIT, Bengaluru for her valuable guidance during the course of this project work and continuous suggestions to make my project work successful. I also extend my sincere thanks to. ANIL KUMAR R, Assistant professor, Civil Engineering, MSRIT, for his constant support. I am also thankful to the teaching and non-teaching staff members who have contributed to the success of this project work.

Finally, I am thankful my parents, friends and relatives who have constantly motivated and supported me and provided me with the best of opportunities in life to achieve my dreams.

NAGASHREE B

(1DA13CSE11)

ABSTRACT Light weight concrete is most often used in civil engineering field in recent days due to its low density and less weight compared to the normal conventional concrete. The present experimental scenario deals with the investigation on the development of light weight concrete by combining two types of light weight aggregates of which, one is naturally occurring and the other is artificially occurring. Light expanded clay aggregates (LECA) is the natural aggregate and cinder is the artificial aggregate which is used in the experimental program. The light weight aggregates are blended proportionately as the full replacement for the normal conventional coarse aggregate as per the mix design carried out for the conventional M20 and M30 grades of concrete. The replacement of light weight aggregates are carried out by varying the percentages of both leca and cinder by weight as (0,100), (10,90), (20,80), (30,70), (40,60), (50,50), (60,40), (70,30), (80,20), (90,10), (100,0) respectively. For M20 and M30 grade of concrete trial mixes; cubes, cylinders and prisms were casted for the normal conventional concrete as well as for the light weight concrete of various proportions by varying the percentages of leca and cinder. From the results we can analyze that with 40% replacement of leca and 60% replacement of cinder aggregates in place of normal coarse aggregates have given better results with high strength, less weight and low density.

CONTENTS CERTIFICATE-----------------------------------------------------------------------------------I DECLARATION--------------------------------------------------------------------------------II ACKNOLEDGEMENT------------------------------------------------------------------------III ABSTRACT-------------------------------------------------------------------------------------IV LIST OF FIGURES---------------------------------------------------------------------------VIII LIST OF GRAPHS-----------------------------------------------------------------------------IX LIST OF TABLES-----------------------------------------------------------------------------XI

Chapter 1 1.0. INTRODUCTION--------------------------------------------------------------------------1 1.1. Introduction-------------------------------------------------------------------------1 1.2. Concrete-----------------------------------------------------------------------------2 1.3. Types of concrete------------------------------------------------------------------3 1.4. Light weight concrete-------------------------------------------------------------3 1.5. Classification of light weight concrete------------------------------------------4 1.5.1. Light weight aggregate concrete------------------------------------------4 1.5.2. Aerated concrete-------------------------------------------------------------4 1.5.3. No fines concrete------------------------------------------------------------5 1.6. Types of light weight aggregates------------------------------------------------6 1.6.1. Natural aggregates----------------------------------------------------------6 1.6.2. Artificial aggregates--------------------------------------------------------6 1.7. LECA-------------------------------------------------------------------------------6 1.7.1. Pyroclastic process of production of leca--------------------------------7 1.7.1.1. Schematic view of pyroclastic process of production of leca-----------------------------------------------------------7 1.7.2. Properties of leca-------------------------------------------------------9 1.7.3. Advantages of leca-----------------------------------------------------9 1.7.4. Applications of leca----------------------------------------------------9 1.8. CINDER---------------------------------------------------------------------------10

1.8.1. Properties of cinder--------------------------------------------------------10 1.8.2. Advantages of cinder------------------------------------------------------11 1.8.3. Applications of cinder---------------------------------------------------11 1.9. Advantages of light weight concrete-----------------------------------------12 1.10. Disadvantages of light weight concrete------------------------------------12 1.11. Applications of light weight concrete--------------------------------------12 1.12. Aim of the work---------------------------------------------------------------13 1.13. Objective-----------------------------------------------------------------------13 Chapter 2 2.0. LITERATURE REVIEW---------------------------------------------------------------14 Chapter 3 3.0. MATERIALS AND METHODOLOGY----------------------------------------------17 3.1. Introduction---------------------------------------------------------------------------17 3.2. Materials used-------------------------------------------------------------------------17 3.3. Properties of raw materials----------------------------------------------------------17 3.4. Methodology--------------------------------------------------------------------------24 3.4.1. Introduction-----------------------------------------------------------24 3.4.2. Preparation of fresh concrete---------------------------------------25 3.4.2.1. Sampling of materials------------------------------------25 3.4.2.2. Proportioning of materials-------------------------------25 3.4.2.3. Mixing of raw materials---------------------------------26 3.4.2.4. Consistency of fresh concrete---------------------------26 3.4.3. Tests on hardened concrete-----------------------------------------26 3.4.3.1. Preparation of moulds------------------------------------27 3.4.3.2. Compaction------------------------------------------------27 3.4.3.3. Demoulding and curing of concrete--------------------27

Chapter 4 4.0. MIX DESIGN-----------------------------------------------------------------------------29 4.1. Mix design for M20 grade concrete--------------------------------------------29 4.2. Mix design for M30 grade concrete--------------------------------------------31 Chapter 5 5.0. EXPERIMENTAL ANALYSIS--------------------------------------------------------35 5.1. Introduction--------------------------------------------------------------------------------35 5.2. Tests on fresh concrete-------------------------------------------------------------------35 5.3. Tests on hardened concrete--------------------------------------------------------------36 5.3.1. Compression strength test----------------------------------------------------36 5.3.2. Split tensile test on hardened concrete--------------------------------------38 5.3.3. Flexural test on hardened concrete------------------------------------------41 Chapter 6 6.0. RESULTS AND DISCUSSIONS-------------------------------------------------------42 6.1. Introduction---------------------------------------------------------------------------------42 6.2. Tests on fresh concrete--------------------------------------------------------------------42 6.3. Tests on hardened concrete---------------------------------------------------------------45 Chapter 7 CONCLUSIONS--------------------------------------------------------------------------------69 REFRENCES------------------------------------------------------------------------------------70

LIST OF FIGURES Fig1.1Light weight aggregate concrete------------------------------------------- 5 Fig1.2 Aerated concrete------------------------------------------------------------- 5 Fig1.3No fines concrete------------------------------------------------------------ 5 Fig 1.4Leca aggregates------------------------------------------------------------- 8 Fig1.5 Cinder aggregate------------------------------------------------------------- 10 Fig 3.1Mixing of materials--------------------------------------------------------- 28 Fig 5.1Slump cone test process---------------------------------------------------- 35 Fig 5.2Compression testing machine--------------------------------------------- 36 Fig 5.3Concrete cubes freshly prepared------------------------------------------ 37 Fig 5.4 Air dried concrete cubes ready for curing------------------------------- 37 Fig 5.5Cubes kept in curing tank for curing------------------------------------- 37 Fig5.6 Concrete cylinders freshly prepared-------------------------------------- 38 Fig5.7Cylinder moulds ready for testing----------------------------------------- 38 Fig5.8 Cracking of Specimen at failure------------------------------------------- 39 Fig 5.9Cylinder after failure(100% leca and 0% cinder proportion)--------- 40 Fig5.10Cylinder after failure(100% cinder and 0% lecaproportion)--------- 40 Fig 5.11 Flexural test on concrete prisms----------------------------------------- 41

LIST OF GRAPHS Graph3.1. Sieve analysis of fine aggregates--------------------------------------------------20 Graph3.2. Sieve analysis of coarse aggregates (gravel) ------------------------------------21 Graph3.3. Sieve analysis of leca----------------------------------------------------------------23 Graph3.4. Sieve analysis of cinder-------------------------------------------------------------24 Graph6.1. Slump values verses aggregate proportion for M20 grade concrete-----------43 Graph6.2. Slump values verses aggregate proportion for M30 grade concrete-----------43 Graph6.3. Comparison of slump values for both M20 and M30 grade Concrete w.r.t the aggregate proportion------------------------------------------44 Graph6.4.Comparison of aggregate proportion verses compressive strength for 7, 14 and 28 days for M20 grade concrete-----------------------------48 Graph 6.5.Comparison of aggregate proportion verses density for 7, 14 and 28 days for M20 grade concrete-----------------------------------------49 Graph 6.6.Comparison of aggregate proportion verses compressive strength for 7, 14 and 28 days for M30 grade concrete------------------------------53 Graph 6.7.Comparison of aggregate proportion verses density for 7, 14 and 28 days for M30 grade concrete ----------------------------------------53 Graph 6.8 Comparison of compressive strength values for M20 and M30 grade concrete for 28 days of curing----------------------------------54 Graph 6.9 Comparison of densities for M20 and M30 grade concrete for 28 days of curing----------------------------------------------------------55 Graph 6.10 Comparison of aggregate proportion verses split tensile strength for 7, 14 and 28 days for M20 grade concrete---------------59 Graph 6.11 Comparison of aggregate proportion verses split tensile strength for 7, 14 and 28 days for M30 grade concrete---------------59 Graph 6.12 Comparison of split tensile strength values for

M20 and M30 grade concrete for 28 days of curing---------------------------------64 Graph 6.13Comparison of aggregate proportion verses flexural strength for 7, 14 and 28 days for M20grade concrete----------------------------65 Graph 6.14Comparison of aggregate proportion verses flexural strength for 7, 14 and 28 days for M30grade concrete---------------------------66 Graph 6.15Comparison of aggregate proportion verses flexural strength for M20 and M30grade concrete for 28 days curing period-----------68

LIST OF TABLES Table 3.1 Comparison of basic properties of cement with standard values------------------------------------------------------------18 Table 3.2.Properties of fine aggregates as per the tests conducted-------------------------18 Table 3.3 Standard values of fineness modulus-----------------------------------------------19 Table 3.4 Sieve analysis of fine aggregates----------------------------------------------------19 Table 3.5 Grading of sand with respect to the cumulative percentage passing as per codal provision------------------------------20 Table 3.6 Properties of coarse aggregates (gravel) as per the tests conducted------------20 Table 3.7 Sieve analysis of gravel---------------------------------------------------------------21 Table 3.8 Standard sizes of coarse aggregates as per is 383-1970--------------------------22 Table 3.9 Properties of leca as per the tests conducted---------------------------------------22 Table 3.10 Sieve analysis of Leca---------------------------------------------------------------22 Table 3.11 Properties of cinder as per the tests conducted-----------------------------------23 Table 3.12 Sieve analysis of cinder-------------------------------------------------------------24 Table 4.1 Proportioning of the materials for M20 grade light weight concrete per m3------------------------------------------------------------31 Table 4.2 Proportioning of the materials for M30 grade light weight concrete per m3------------------------------------------------------------34 Table 4.3 Summary of the mix design per m3-------------------------------------------------34 Table 6.1.Slump for M20 and M30 grade light weight aggregate concrete-----------------42 Table 6.2 Compression test on M20 grade concrete for 7 days------------------------------45 Table 6.3 Compression test on M20 grade concrete for 14 days----------------------------46 Table 6.4 Compression test on M20 grade concrete for 28 days----------------------------47 Table 6.5 Compression test on M30 grade concrete for 7 days------------------------------50 Table 6.6 compression test on M30 grade concrete for 14 days-----------------------------51

Table 6.7 Compression test on M30 grade concrete for 28days-----------------------------52 Table 6.8 Split tensile test for 7 days M20 grade concrete -----------------------------------56 Table 6.9.Split tensile test for 14 days M20 grade concrete --------------------------------57 Table 6.10.Split tensile test for 28 days M20 grade concrete ------------------------------58 Table 6.11.Split tensile test for 7 days M30 grade concrete -------------------------------61 Table 6.12.Split tensile test for 14 days M30 grade concrete ------------------------------62 Table 6.13 Split tensile test for 28 days M30 grade concrete ------------------------------63 Table 6.14 Flexural strength test for M20 grade concrete----------------------------------65 Table 6.15 Flexural strength test for M30 grade concrete----------------------------------67

EXPERIMENTAL INVESTIGATION ON DEVELOPMENT OF LIGHT WEIGHT CONCRETE BY BLENDING WITH LECA AND CINDER.

Chapter 1

INTRODUCTION 1.1.

Introduction Concrete is basic important adhesive material used in building of various

civil engineering structures. It is obtained by mixing cement, fine aggregates (sand), coarse aggregates (jelly) and water along addition of some pozzolonas if required in a proportionate way as per the mix design. Increased demand in the construction industry lead to increase in the cost of production of concrete .This increase in cost of construction materials have paved the way for the researchers to introduce some new construction materials with low cost and high strength. Concrete, due to its high self weight increases the dead load on the structure, and many research works have been carried out in order to reduce the self weight of the construction materials on the structure, which lead to the development of light weight concrete. With reference to this there is an increase in the demand for light weight concrete. Concrete, whose density (1440 to 1840 kg/m3) is lesser when compared to the normal conventional concrete(2240 to 2400 kg/m3), is termed as light weight concrete. Light weight structural concrete is an enhanced version of concrete, with emphasis on decrease in density of concrete. When structural concerns require a minimum increase to the dead load, light weight concrete is used. Many research works have been carried out to produce light weight concrete using different types of aggregates like leca cinder, pumice etc… Some research works are carried out with leca (Sivakumar et.al [2011]) or cinder (Rathish Kumaret.al [2011])) as coarse aggregates for conventional aggregate replacement. In the present experimental work leca and cinder are used as coarse aggregates replacing the conventional coarse aggregate in different proportions. Mix design is carried out for the normal conventional concrete of different grades, and then the coarse aggregate proportion is completely replaced by blended light weight aggregates such as leca and cinder in different proportions. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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Further tests have been conducted in order to determine the fresh and hardened properties of concrete and then results are compared with that of results obtained for normal conventional concrete.

1.2. Concrete Concrete is a composite material and is an analogous mixture of cement, fine aggregates, coarse aggregates and water. The word concrete is derived from a Latin word “concretus”, which means dense and thick. Mixing of raw materials in a definite proportion shall result in good quality of concrete. Due to hydration reaction between the raw materials, concrete hardens, and this reaction continues to the duration where maximum strength is reached. Hardened concrete can also be used as aggregates for light construction practices. Since concrete possess larger value of young’s modulus, it can be considered as a major supporting material for construction and also the medium for stress transfer. Concrete has higher compressive strength and lower tensile strength. The tensile strength of concrete can be increased by introduction of steel bars in it which are technically termed as reinforcements. Sometimes the tensile stresses are taken care of introduction of compressive stress in concrete since the initial compressive stress neutralizes the tensile stresses as in case of prestressed concrete construction. Concrete with inclusion of reinforcements are known as Reinforced Cement Concrete (RCC) and those without reinforcement are known as Plain Cement Concrete (PCC).The concrete which are used for construction of various structures such as bridges, dams etc… act as integral part of the structure for taking the load of it and are known as Structural Concrete. The major benefit of concrete is that it can be moulded at site in any shape and dimension providing high compressive strength. Disadvantage is the relatively high density related to its high compressive strength. However, density can be decreased or strength can be increased considerably by altering some of the concrete properties. For example light weight concrete, vacuum concrete etc……... DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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1.3. Types of concrete: Based on the materials used in the production, its performance, resistance against loading, concrete can be classified as 1) High performance concrete. 2) Self compacting concrete. 3) Light weight concrete. 4) Fibre reinforced concrete 5) Shotcrete. 6) Ultra high performance concrete. 7) Self consolidating concrete. 8) Limecrete. 9) Pervious concrete. 10) Vacuum concrete. Among these different types of concrete, light weight concrete is considered for the present work.

1.4. Light weight concrete: The concrete which is of low density and less weight due to the presence of large amount of air voids in it is known as light weight concrete. It can also be defined as the concrete whose density (1440 to 1840 kg/m3) is comparatively minimal to the normal conventional concrete (2240 to 2400 kg/m3) is termed as light weight concrete. The composition of this type of concrete is similar to that of conventional concrete except the use of light weight aggregates or combination of both light weight aggregates and regular aggregates. In some cases, the fine aggregate portion is replaced by light weight products. Now a days usage of light weight concrete has been gradually increased due to low density, improved durability and cost effectiveness of the structure. Light weight aggregates used for structural light

DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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weight concrete are generally expanded shale(sp gravity :1.590), slate(sp gravity :1.670), cinder(sp gravity :1.263), pumice(sp gravity :0.64) etc…. .

1.5. Classification of light weight concrete: Based on the method of production, light weight concrete are classified as follows; 1) Light weight aggregate concrete. 2) Aerated concrete. 3) No fines concrete.

1.5.1. Light weight aggregate concrete: The concrete, which uses light weight aggregates for its production is known as light weight aggregate concrete. Since the density of this type of concrete is varied with that of normal conventional concrete, henceforth various properties of this type of concrete is varied as when compared to the normal concrete. Aggregates used for production of this type of concrete are pumice (sp gravity: 0.64), leca (sp gravity: 0.98), cinder (sp gravity: 1.60), perlite etc…. . Generally the light weight aggregates will have angular shape and uneven surface which produce the good quality of concrete with high workability. For good workability, natural sand is preferably used instead of sand made out of crushed light weight aggregates. Intrusion of air into the concrete also increases workability but results in decrease in strength of concrete.

1.5.2. Aerated concrete: This type of concrete is fabricated by mixing of the raw materials of concrete along with addition of some expanding agent which causes the resulting product to increase its volume. It is also entitled as gas concrete, foam concrete, cellular concrete. The gaseous foam which is formed is mixed with slurry and the finely powdered metal is added in order to react with calcium hydroxide to liberate hydrogen gas. This hydrogen gas, when contained in slurry gives the cellular state.


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Gasification method (as mentioned above) is widely used to get cellular concrete. This method is most oftenly used in factories for large scale manufacture of aerated concrete which is then subjected to high steam curing. The concrete of any desired density can be prepared by this method.

1.5.3. No fines concrete: The concrete which do not include fine aggregate proportion from the mixture is termed as “No fines concrete”. Thus this concrete is made of cement, water& coarse aggregates. Generally the coarse aggregates of size passing through 20mm and retained on 10mm is used. No fines concrete is well accepted, since it possesses more advantages. As mentioned above, the coarse aggregates used in no fines concrete is preferably of single fraction, so that it gives good attractive look & can also be used for decorative purposes.

Fig1.1.Light weight aggregate

Fig1.2. Aerated concrete

Concrete

Fig1.3.No fines concrete DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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1.6. Types of light weight aggregates Light weight coarse aggregates are classified into two groups they are natural aggregates & artificial aggregates.

1.6.1. Natural aggregates: The aggregates which are of volcanic origin and are not of uniform quality, shape and size are known as Natural aggregates. The hot volcanic lava explodes, the molten material cools and forms a hard rocky state. Low density of these aggregates is due to existence of air voids in the fluid magma which is captivated during cooling. Some of the natural light weight aggregates are pumice (sp gravity: 0.64), diatomite (sp gravity-1.25), tuff (sp gravity-0.40) etc….

1.6.2. Artificial aggregates: The aggregates which are not of natural origin, but are manufactured artificially are known as artificial aggregates. Some of the artificial aggregates are brick bats, foamed slag, expanded perlite etc…. In the present experimental program the combination of both natural (cinder) and artificial (leca) light weight aggregates are used as coarse aggregates.

1.7. LECA: It is abbreviated as LIGHT EXPANDED CLAY AGGREGATES or generally referred as EXPANDED CLAY. It is the type of artificial light weight aggregate which are obtained by baking the raw material i.e. clay at very high temperature (12000C) in the rotary kiln. The process of manufacture of leca is popularly known as pyroclastic process. The expulsion of gases during the baking process of clay will result in formation of small vesicles which therefore forms a honey combed pattern on the end product.

1.7.1. Pyroclastic process of production of leca: The raw material .i.e. clay which is free from impurities is taken with a desired quantity and then the water is added to a required consistency, so that the resulting plastic state of clay should be free from lumps as shown in schematic view (i)


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The clay is then taken to the preheated rotary kiln through a transport system and then it is baked to a temperature of about 12000C (ii).The clay, when subjected to such a high temperature expands and expels the gases through the air vent as a result there is the formation of small cavities in the clay resulting to a honey combed structure (iii). The resulting clay is then cooled, so that it hardens to form the end product LECA ( iv, v, vi).

1.7.1.1. Schematic view of pyroclastic process of production of leca

(i)

(iv)

(v) DR AMBEDKAR INSTITUTE OF TECHNOLOGY

(ii)

(iii)

(vi) Page 7


Fig 1.4.Leca aggregates DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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1.7.2. Properties of leca 1) Although leca is a lightweight aggregate, the porosity of it is more & hence density of it is less 2) It is having high quality of thermal insulation. 3)

The researchers have proved that it has good sound insulation property.

4) Since it is processed in rotary kiln at high temperature during its manufacturing, hence the structures made up of it can have better fire resistance. 5)

It can resist the acid & alkali attacks without decomposing.

6) Since the degree of porosity is high, the percentage of water absorption will also be high.

1.7.3. Advantages of leca: 1) Decreases the dead load of the structure. 2) Since it is light in weight, there is decremental effect of earth quake on the structure. It also prevents from asymmetric settlement & detrimental side effects. 3) The structures that are constructed with leca is strong enough & are able to resist the physical operation like cutting, nailing, piping etc…without cracking . 4) Speed of construction is high. 5) Cost of construction is less. 6) Since it is resistant to various chemical attacks, it can be installed easily at any severe climatic conditions.

1.7.4. Applications of leca: 1) In recent days the structures are constructed with light weight aggregates in order to decrease the dead load of the structure. Hence it has wide applications in construction field. 2) It is also used in the pavement construction. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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3) Due to its light in weight, decomposable nature, thermal insulating property and structural stability it can be used for flooring & roofing. 4) It can be also used in agricultural field. 5) Due to its porous nature, it can be used in house waste water treatments as filters.

1.8. CINDER: The volcanic eruptions from the cone shaped peaks known as cinder cone or scoria cone, sprays the lava of the melted rocks and cooling of it results in formation of highly vesicular, glassy natured, light weight rock which is termed as cinder. It is also called by name scoria. Cinder is the most commonly occurring igneous rock. Due to its high porosity and it is less dense; it can be used as light weight aggregate.

Fig1.5. Cinder aggregate

1.8.1. Properties of cinder: The following are some of the properties of cinder 1) Cinder aggregates possess high porosity and low density. 2) It is having high thermal insulation property. 3) It has good acoustic property. 4) It is generally black or red in color. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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5) It is having good fire resistant property. 6) Cinder has less water absorption capacity. 7) It is resistant to freezing and thawing effect. 8) It has good binding property with cement.

1.8.2. Advantages of cinder: 1) Structures build with cinder blocks are much more durable than brick, clapboard or plastic-shingled & wooden structures. 2) Structures build with cinder blocks are resistant to fire, earthquakes & strong wind. 3) Cinder block homes don’t have typical problems of termites and warping like wooden counterparts. 4) All cinder block homes are built to maximize energy efficiency. Air penetration in homes is known to cause up to a 39 percent energy loss, according to experts at concrete block homes. Cinder block homes are airtight and virtually free of drafts. 5) Cost of construction using cinder blocks is less. 6) Maintenance cost is less.

1.8.3. Applications of cinder: 1) One of the main uses of cinder is the production of lightweight aggregate. 2) Crushed cinder is used as roofing granules, ground cover in landscape projects and as a substrate in hydroponic gardening. 3) Cinders can efficiently trap air in it; hence it is used as air insulator. 4) Cinder is also used as rip-rap, drainage stone and low-quality road metal. 5) Small amounts of cinder are used as sauna rock and as a heat sink in barbecue grills. 6) It is used in manufacture of precast RCC lintels. 7) Used in manufacture of readymade building blocks & partition wall panels.


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1.9. Advantages of light weight concrete 1) Decreases dead load of the structure. 2) Possess high seismic resistance. Since low density concrete can absorb more loads without any fracture of the structure. 3) It has more sound absorption capacity, since it consists of many interfaces, hence transmission of sound can be at large extent. 4) Due to its light weight, transportation & placing of concrete is easier. 5) It possesses higher fire resistance, due to lower thermal conductivity. 6) Due to its porous nature, it can be repaired without any difficulty.

1.10. Disadvantages of light weight concrete: 1) It is very risky to place the light weight concrete, since it contains high volume of air voids in it. 2) Chances of segregation of aggregates from the cement paste are most often found in this type of concrete. 3) Time of mixing is very much sustained than compared to the normal concrete. 4) Due to its high porosity, absorption of water content is more than conventional concrete.

1.11. Applications of light weight concrete: Light weight concrete has many applications as follows 1) Light weight concrete is used in bridge abutment. 2) It can be used as a packing material i.e. can be used to fill voids. 3) Due to its good acoustical property, it can be used as a sound proof material. 4) It can also be used for Heat insulation on roofs. 5) It is also used for Trench Reinstatement. 6) Light weight concrete is widely used in the construction of water retaining structures, docks and harbors, dams, bridges, bunkers and silos, etc. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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1.12. Aim of the work: Light weight concrete has vast applications in various fields due to its low density. The aim of experiment is to develop the light weight concrete for the mix design of conventional concrete such as M20& M30 by full replacement of the portion of coarse aggregates (granite) by blending of light weight aggregates such as LECA & CINDER with different percentages & thereby achieving the target strength with low density of concrete.

1.13. Objective: The objective of the experimental program is discussed as follows: 1) To develop light weight structural concrete by blending with LECA and CINDER for M20 & M30grade of concrete. 2) To produce light weight structural concrete by varying proportions of LECA and CINDER in order to obtain optimum strength with less density. 3) To study the properties of fresh and hardened concrete.


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Chapter 2

LITERATURE REVIEW Various researchers have carried out experimental investigation to study the properties of light weight structural concrete with light weight aggregates. 1) Sivakumar et.al[2015]- The author has used leca as the replacement aggregate in place of coarse aggregate in order to develop the light weight aggregate concrete. In addition to leca, it also uses fly ash and bottom ash as the mineral admixtures. The experiment is done for M20 grade concrete by utilizing fly ash as the replacing material for cement, bottom ash in place of fine aggregates and leca in place of coarse aggregates at the rate of 5%, 10%, 15%, 20%, 25%, 30% and 35%.the compressive strength, split tensile strength and flexural strength tests are carried out for 7, 28 and 56 days of curing period. For the 5% replacement of fly ash, bottom ash and leca the optimum strength is observed. 2) Rathish Kumar et.al [2012] - The light weight aggregate concrete is developed by using cinder as the coarse aggregate and replacement of cement by fly ash. In this study the light weight concrete is developed for both M20 and M30 grade concrete by varying the size of cinder aggregates. The compressive strength, split tensile strength tests were performed for 3, 7 and 28 days of curing period. The results shows that with 30% replacement of fly ash gives better performance for both the grades of concrete and with 12.5mm size cinder aggregate for M20 grade concrete and 10mm size cinder aggregate for M30 grade concrete gives good strength. 3) Siva LingaRao et.al [2011]-In this journal the analysis is done by conducting the mix design for the normal conventional M20 grade concrete and then replacing the normal coarse aggregate proportion by cinder aggregates by varying the percentages such as 20,40,60,80,100 and cement proportion is replaced by silica fume by varying the percentages as 0, 5, 10, 15 and 20.Tests on the hardened concrete such as cube compression, split tensile, flexural strength tests is carried out in order to determine the optimum proportion of the mix. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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The experimental analysis concluded that with 60% replacement of cinder and 10% replacement of silica fume gives the best results. 4) PayamShafigh et.al [2011]-the light weight concrete beams, which are made of light weight aggregate such as leca, are analysed in this journal paper. The paper compares flexural investigation on the performance of the analysed beam with the predicted theoretical results. Nine reinforced concrete beams were manufactured and were tested under two-point loads, which were kept at 600 mm apart on a span of 1800 mm under a load control mode with 10 to 15 KN increments until failure. A testing machine of capacity of 500 KN with built-in load cell was used in the testing. All deflections and loads were recorded using a data logger. The concrete strength and steel bar reinforcement were two important parameters examined during the beam tests. According to this study, the results shows that the LECA lightweight concrete had a compressive strength in range of 37 to 62 MPa and an air dry density of 1600 to 1850 kg/m3. 5) Hossain et.al [2011]-in this journal paper the coarse aggregate and fine aggregate proportion in the normal conventional concrete is replaced by the volcanic pumice coarse aggregate and the volcanic pumice fine aggregates respectively. The replacement percentages are 0%,25%,50%,75%,100% by volume for both coarse and fine aggregates with constant water cement ratio. The 28-day density, compressive/tensile strength and modulus of elasticity decreased with the increase of pumice aggregate as replacement of normal coarse gravel aggregate/fine aggregate (sand)/both.The use of volcanic pumice coarse and fine aggregates, 20% pumice lowers the density, compressive/tensile strength and modulus of elasticity of pumice coarse aggregate mixtures. Wide range of VPC mixtures satisfies the requirement of lightweight structural concrete. 6) Clinker Bhasar et.al, 2012- The aim of this research paper was to investigate on the rapid chloride permeability test on lightweight concrete produced from oil palm clinker aggregates. Oil palm clinker is obtained from by-product of palm oil milling. The author says utilizing oil palm clinker in concrete production not only solves the problem of disposing this solid waste but also help to converse natural resources. The parameter of investigation included rapid chloride permeability test DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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for a period of 7 days, 28 days, and 90 days.3 oil palm clinker concrete specimens of 100 X 50 mm cylinders were cast and tested. The chloride permeability values of oil palm clinker concrete were compared to ASTM C1202 criteria. The result from this study showed that the chloride permeability value of oil palm clinker concrete to be used as aggregate in production of durable structural lightweight concrete. 7) SerkanSuba (2009)-In this study, the effect of using fly ash in high strength lightweight aggregate concrete produced with expanded clay aggregate on physical and mechanical properties of the concrete was investigated. For this purpose, lightweight concrete mixtures with 350, 400 and 450 kg/m3 cement content were prepared using expanded clay aggregate. Besides, concretes with 0, 10, 20 and 30% fly ash replacement were produced out of the mixtures with different cement contents. Concrete density, porosity, ultrasonic pulse velocity, compressive and split tensile strength experiments were performed on the prepared.

From the above literature survey it is observed that, the researchers have studied either leca or cinder as the light weight aggregate as the replacement for normal conventional coarse aggregates. Hence in the present experimental program, an attempt is made to use both leca as well as cinder in different proportions as the replacement for normal conventional coarse aggregates.


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Chapter 3

MATERIALS AND METHODOLOGY 3.1. Introduction: In this chapter we are going to study the properties of raw materials and also the methodology of the present experimental program.

3.2. Materials used: The raw materials, along with their specifications and properties which are used for the experiment are discussed below 1) Cement-Ordinary Portland cement 43 grade confirming to IS 12269-1987. 2) Fine aggregates –Aggregates passing through 4.75mm IS sieve and retained on 2.36mm IS sieves are taken. 3) Coarse aggregates –Normal aggregates passing through 12mm IS sieve and retained on 10 mm IS sieve are taken. 4) Light weight aggregates used in experimentation-LECA & CINDER as replacement to normal coarse aggregates

3.3. Properties of raw materials: The physical properties of raw materials are determined by conducting some basic tests such as fineness test, soundness test, setting time, standard consistency, specific gravity and compressive strength for cement; specific gravity, sieve analysis and moisture content tests for both fine aggregates and coarse aggregates. The results obtained from the above all basic tests on the raw materials are compared with the standard values which are mentioned in the respective codal provisions. If the results obtained from the test results are comparable to the standard values in the codal provisions then the raw materials can be satisfactorily used for the experimental studies. If not, the raw materials are discarded and then the new materials are used for the preparation of concrete.


Page 17


Table 3.1.Comparison of basic properties of cement with standard values

SL no

Name of test

Value obtained

Standard value as per IS 8112 : 2013

1

Fineness of cement

3.5%

Should not be more than 10%.

2

Soundness of cement

4mm

Should not be more than 10mm.

3

Initial setting time

38 min

Should not be less than 30min

Final setting time

435 min

Should not be more than 600 min

4

Standard consistency

30%

Should be between 29-32%.

5

Specific gravity

3.142

Not specified by code.

6

Compressive strength for 28

67N/mm2

Should not be less than 53N/mm2

days

Table 3.2.Properties of fine aggregates as per the tests conducted.

SL no

Name of test

Value obtained

1

Specific gravity

2.55

2

Fineness modulus

3.258%

3

Water absorption

1.523%


Page 18


Table 3.3 Standard values of fineness modulus. Sl. No.

Type of Sand

Fineness Modulus as per IS 383-1970

1

Fine

2.0 to 2.5

2

Medium

2.5 to 3.2

3

Coarse

3.2 and above

Table 3.4 Sieve analysis of fine aggregates:

Sl no

Sieve

Weight of

% weight of

Cumulative

% of sand passing

size

sand retained

sand

% of sand

through sieve

in each sieve

retained

retained

(gm)

1

4.75mm

19

1.9

1.9

98.1

2

2.36mm

24

2.4

4.3

95.7

3

1.18mm

122

12.2

16.5

83.5

4

600µ

330

33.0

49.5

50.5

5

300µ

258

25.8

75.3

24.7

6

150µ

222

22.2

97.5

2.5

7

Pan

25

2.5

100

0


Page 19


100.00 90.00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00 0.10

1.00

percentage passing

Sieve analysis of fine aggregates

10.00

sieve size(mm)

Graph3.1. sieve analysis of fine aggregates.

Table 3.5 Grading of sand with respect to the cumulative percentage passing as per codal provision. Zone

Sieve size

Cumulative passing %

ZONE1

600 micron

15-34

ZONE2

600 micron

35-59

ZONE 3

600 micron

60-79

From the above table it can be concluded that the fine aggregates taken to the experimental study confirm to zone 2 fraction as per IS 383-1970. Table 3.6Properties of coarse aggregates (gravel) as per the tests conducted.

SL no

Name of test

Value obtained

1

Specific gravity

2.68

2

Fineness modulus

3.608%

3

Water absorption

0.964%


Page 20


Table 3.7.Sieve analysis of gravel: Sl no

Sieve size Weight of

% weight

Cumulative

% of

aggregate

of

% of

aggregate

retained in

aggregate

aggregate

passing

each sieve

retained

retained

through sieve

(gm)

1

20mm

23

0.23

0.23

99.77

2

12.5mm

1628

16.28

16.51

83.49

3

10mm

3586

35.86

52.37

47.63

4

6.3mm

4087

40.87

93.24

6.76

5

4.75mm

529

5.29

98.53

1.47

6

Pan

147

1.47

100

0

Sieve analysis of gravel 100.00 90.00 70.00 60.00 50.00 40.00 30.00

percentage passing

80.00

20.00 10.00 0.00 1.00

5.00

25.00

sieve size(mm)

Graph3.2. sieve analysis of coarse aggregates (gravel). DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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Table 3.8.Standard sizes of coarse aggregates as per is 383-1970 Sieve size

Class

Percentage passing

80mm passing 40mm retained

Large

90-100

40mm passing 20mm retained

Medium

90-100

20mm passing 4.75mm retained

Small

90-100

From the above table it can be concluded that the coarse aggregates which are taken in the experimental program are 20mm passing and 4.75mm retained on IS sieves. Table 3.9 Properties of leca as per the tests conducted.

SL no

Name of test

Value obtained

1

Specific gravity

0.98

2

Fineness modulus

4.688%

3

Water absorption

17.08%

Table 3.10Sieve analysis of Leca: Sl

Sieve

Weight of

% weight

Cumulati

% of

Specifications

no

size

aggregate

of

ve % of

aggregate

as per IS 9142-

retained in aggregate

aggregate passing

each sieve

retained

retained

(gm)

1979

through sieve

1

20mm

200

2.00

2.00

98.00

90-100

2

12.5mm

7005

70.05

72.05

27.95

40-80

3

10mm

2435

24.35

96.4

3.60

0-20

4

6.3mm

235

2.35

98.75

1.25

0-10

5

4.75mm

85

0.85

99.6

0.40

---

6

Pan

40

0.40

100

0.0

---

From the above table the leca aggregates of 20mm passing and 12.5mm retained aggregates are taken for consideration for the experimental study. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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Sieve analysis of leca

1.00

5.00 sieve size(mm)

percentage passing

100.00 90.00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00 25.00

Graph3.3. sieve analysis of leca.

Table 3.11Sieve analysis of cinder: Sl

Sieve

Weight of % weight

Cumulative

% of

Specifications

no

size

aggregate

of

% of

aggregate

as per IS 2686-

retained

aggregate

aggregate

passing

1977

in each

retained

retained

through

sieve

sieve

(gm) 1

20mm

50

0.50

0.50

99.50

80-100

2

12.5mm

8155

81.55

82.05

17.95

60-79

3

10mm

1540

12.00

94.05

5.95

40-59

4

6.3mm

130

4.70

98.75

1.25

30-39

5

4.75mm

100

1.00

99.75

0.25

25-29

6

Pan

25

0.25

100

0

16-24

From the above table the cinder aggregates of 20mm passing and 12.5mm retained aggregates are taken for consideration for the experimental study. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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100.00 90.00 80.00 70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00 1.00

5.00

percentage passing

Sieve analysis of cinder

25.00

sieve size(mm)

Graph3.4. sieve analysis of cinder.

Table 3.12 Properties of cinder as per the tests conducted.

SL NO

Name of test

Value obtained

1

Specific gravity

1.60

2

Fineness modulus

5.776%

3

Water absorption

9.62%

3.4. Methodology: 3.4.1. Introduction: The methodology of the experimental program deals with preparation of the fresh concrete, tests on fresh concrete, preparation of moulds i.e. cubes, cylinders and prisms in order to determine the compressive strength, split tensile strength and flexural strength of hardened concrete. The raw materials are firstly cleaned, so that it should be free from impurities.


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It is then subjected to some basic tests in order to determine its properties. The materials before mixing are batched proportionately in order to obtain a definite mix. Further the mix design is prepared for the normal conventional concrete of grades M20 and M30.The weight of the coarse aggregate required for the experimental program is calculated by the mix design is then fully replaced by blending of two types of light weight aggregates such as leca and cinder in a proportionate way without changing the water cement ratio.

3.4.2 Preparation of fresh concrete: 3.4.2.1 Sampling of materials: Initially the materials should be carefully sampled from the larger bags; it should be then cleaned and used. The materials which are used for the preparation of concrete shall be maintained to a room temperature, preferably 27° ± 2°C before commencement of the tests. The materials required for preparing fresh concrete, shall be thoroughly mixed dry either by hand or in a suitable mixer in such a manner so as to ensure the greatest possible blending and uniformity in the mix. The cement and other materials shall be stored in a dry place. Samples of aggregates for each batch of concrete shall be graded desirably and shall be in an air-dried condition. In this present investigation the tests have been conducted using fine aggregate, normal coarse aggregates and blending of light weight aggregates (LECA & CINDER) as a replacement of with normal coarse aggregates in various percentages by volume.

3.4.2.2 Proportioning of materials: The materials which are used in the experiment should be correctly weighed according to the mix proportions as mentioned in the mix design. The proportions of ingredients are specified by volume at site, but they are specified by weight in laboratory in order to ease for casting of the moulds.


Page 25


3.4.2.3 Mixing of raw materials: Since it is a light weight aggregate concrete, hand mixing is generally preferred. Because the aggregates due to its low weight and less density may crush when mixed in machine and may decline strength of concrete. The mixing tray is firstly cleaned in order to remove dust and impurities and then the ingredients which are weighed are put into the tray one after the other. Further it is dry mixed in order to obtain the homogenous mix; then the water is added in a correct quantity as mentioned in the mix design and mixed thoroughly till the resulting concrete is of uniform in appearance.

3.4.2.4 Consistency of fresh concrete: Concrete, which is prepared by varying the proportions of leca and cinder aggregates are tested for consistency immediately after mixing. Generally slump cone test is used to measure consistency of concrete. Precautions should be taken that there should not be any loss of the batched materials during the experimentation. If so, then the amount of materials lost should be added to the mix in order to get homogeneity in the mixture.

3.4.3 Tests on hardened concrete: In this section we are going to determine the properties of hardened concrete such as 1) COMPRESSIVE STRENGTH 2) SPLIT TENSILE STRENGTH 3) FLEXURAL STRENGTH

3.4.3.1 Preparation of moulds: The standard sizes of cube moulds 150x150x150mm are used in the experimental program. Generally the moulds are made of cast iron or cast steel. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

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The mould is made of two halves which is rectangular in shape which facilitates the easy removal of the hardened concrete cubes without any damage. Before assembling the moulds, they should be cleaned thoroughly in order to remove previously experimented hardened concrete or dirt on the faces which prevent the sections from fitting together closely. The inner faces and the base of the mould must be coated with thin layer of grease or oil for easy removal of hardened concrete. The sections must be bolted firmly together in order to fit tightly to the base plate.

3.4.3.2 Compaction: Soon after the concrete is mixed, immediately the cubical moulds are filled with fresh concrete and then it is compacted either by hand by using tamping rod or by using vibrators. Air entrainment into the pores will increases the porosity in the concrete and hence reduces the strength of the concrete cubes. Therefore the cubes must me properly compacted in order to avoid the air voids. However precaution must be taken to avoid over compaction of concrete, which may cause segregation of aggregates and the cement paste present in the mix and finally reduces the compressive strength of the concrete.

3.4.3.3Demoulding and curing of concrete: The concrete specimens shall be placed in the place free from vibration and allowed to dry in atmospheric air at the temperature 27oC+_2oC for 24 hours from the time of addition of water to the dry ingredients of the mix. The moulds are then demoulded carefully in such a way that there is no occurrence of damage to the specimens. During demoulding the moulds should not be affected by any cracks, if so then the compressive strength of concrete will be reduced. After demoulding, the moulds should be cleaned properly and the concrete specimens should be marked with colored paints in order for its identification. The demoulded specimens should be kept in the curing tank, which is maintained at the temperature of 27-300C. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 27


In order to maintain proper curing, adequate circulation of water should be provided by maintaining proper spacing between specimens and the side of the tank. Curing should be done properly for the period of 7 days, 14 days and 28 days for the present experimental program.

Fig 3.1.Mixing of materials


Page 28


Chapter 4

MIX DESIGN The mix design of concrete is done as per IS10262:2009 and the calculations and proportioning of the raw materials for M20 and M30 grade of concrete are calculated as shown in table

4.1. Mix design for M20 grade concrete Stipulations for Proportioning 1

Grade Designation

M20

2

Type of cement

OPC 43 grade confirming to IS 8112

3

Maximum nominal size of aggregates

20 mm

4

Minimum cement content

320 kg/m3

5

Maximum water cement ratio

0.5

6

Workability:

75 mm (slump)

7

Exposure condition

Mild

8

Degree of supervision

Good

9

Type of aggregate

Crushed angular aggregate

10

Maximum cement content

450 kg/m3

11

Chemical admixture

Not recommended

Test Data For Materials 1

Cement used


2

Specific gravity of cement

3.142

3

Specific gravity of Coarse aggregate

2.68

4

Specific gravity of Fine aggregate

2.55

5

Water absorption Coarse aggregate

0.964 percent


Page 29


6

Water absorption Fine aggregate

1.523 percent

7

Free (surface) moisture Coarse

Nil (absorbed moisture full)

aggregate 8

Sieve analysis Coarse aggregate

Conforming to Table 2 of IS: 383

9

Sieve analysis Fine aggregate:

Conforming to Zone II of IS: 383

Target Strength For Mix Proportioning 1

Target Mean Strength

26.60 N/mm2

2

Characteristic Compressive Strength @

20 N/mm2

28 days Selection Of Water Cement Ratio 1

Maximum Water Cement Ratio

0.5

2

Adopted Water Cement Ratio

0.5

Selection Of Water Content `1

Maximum Water Content

186 liters

2

Estimated water content for 75 mm

191.6 liters

slump Calculation Of Cement Content 1

Water cement ratio

0.50

2

Cement content

383 kg/m3 >320 kg/m3 (given)

From Table 5 of IS: 456, minimum cement content for mild exposure condition= 300 kg/m3 Proportion Of Volume Of Coarse Aggregate And Fine Aggregate Content 1

Vol. of Coarse Aggregate as per

60.00%

table 3 of IS 10262 2

Adopted Vol. Coarse Aggregate

60.00%

3

Adopted Vol. Fine Aggregate

40.0%


Page 30


Mix Calculations

T

1

Volume of concrete in m3

1 m3

2

Volume of cement in m3

0.122 m3

3

Volume of water in m3

0.192 m3

a

4

Volume of all in aggregates in m

b

5

Volume of coarse aggregates in kg Volume of fine aggregates in kg

l e

6

3

0.686 m3 1103 kg 700 kg

Table 4.1Proportioning of the materials for M20 grade light weight concrete per m3 Leca

in cinder

in Leca

percentage percentage (kg)

Cinder

Cement

Sand

(kg)

(Kg)

(kg)

Water

0

100

0

1103

383

700

191.6

10

90

110.3

992.7

383

700

191.6

20

80

220.6

882.4

383

700

191.6

30

70

330.9

772.1

383

700

191.6

40

60

441.2

661.8

383

700

191.6

50

50

551.5

551.5

383

700

191.6

60

40

661.8

441.2

383

700

191.6

70

30

772.1

330.9

383

700

191.6

80

20

882.4

220.6

383

700

191.6

90

10

992.7

110.3

383

700

191.6

100

0

1103

0

383

700

191.6

4.2. Mix design for M30 grade concrete Stipulations For Proportioning 1

Grade designation

M30

2

Type of cement

OPC 43 grade confirming IS-12269-1987


Page 31


3

Maximum nominal size of aggregates

20 mm

4

Minimum cement content

350 kg/m3

5


0.50

6

Workability

25 - 50 mm (slump)

7

Exposure condition

Moderate

8

Degree of supervision

Good

9

Type of aggregate

Crushed angular aggregate

10

Maximum cement content

450 kg/m3

11

Chemical admixture

Not recommended

Test Data For Materials 1

Cement used


2

Specific gravity of cement

3.142

3

Specific gravity of Coarse aggregate

2.68

4

Specific gravity of Fine aggregate

2.55

5

Water absorption of Coarse aggregate

0.6 percent

6

Water absorption of Fine aggregate

1.0 percent

7

Free (surface) moisture of Coarse

Nil (absorbed moisture full)

aggregate 8

Free (surface) of Fine aggregate

Nil

9

Sieve analysis of Coarse aggregate

Conforming to Table 2 of IS: 383

10

Sieve analysis of Fine aggregate

Conforming to Zone II of IS: 383

Target Strength For Mix Proportioning 1

Target strength

38.25 N/mm2

2

Characteristic compressive strength at 28 days

30 N/mm2


Page 32


3

Selection Of Water Cement Ratio

4


0.50

5

Adopt water cement ratio

0.50

Selection Of Water Content 1

Maximum water content

208 liters

2

Estimated water content for 25-50 mm slump

186 liters

Selection Of Water Content `1

Maximum Water Content

208liters

2

Estimated water content for 75 mm slump

191.6 liters

Calculation Of Cement Content 1

Water cement ratio

0.50

2

Cement content

416 kg/m3 >320 kg/m3 (given)

From Table 5 of IS: 456, minimum cement content for mild exposure condition = 300 kg/m3, Hence OK Proportion Of Volume Of Coarse Aggregate And Fine Aggregate Content 1

Vol. of Coarse Aggregate as per table 3 of IS

60.00%

10262 2

Adopted Vol. Coarse Aggregate

60.00%

3

Adopted Vol. Fine Aggregate

40.00%

Mix Calculations 1

Volume of concrete in m3

1 m3

2

Volume of cement in m3

0.132 m3

3

Volume of water in m3

0.186 m3


Page 33


4

Volume of all in aggregates in m3

0.682 m3

5

Volume of coarse aggregates in kg

1115 kg

6

Volume of fine aggregates in kg

679 kg

Table 4.2 Proportioning of the materials for M30 grade light weight concrete per m3 Leca

in cinder

in Leca (kg) Cinder (kg)

Cement

Sand

(Kg)

(kg)

Water

percentage

percentage

0

100

0

1115

416

679

186

10

90

111.5

1003.5

416

679

186

20

80

223.0

892.0

416

679

186

30

70

334.5

780.5

416

679

186

40

60

446.0

669.0

416

679

186

50

50

557.5

557.5

416

679

186

60

40

669.0

446.0

416

679

186

70

30

780.5

334.5

416

679

186

80

20

892.0

223.0

416

679

186

90

10

1003.5

111.5

416

679

186

100

0

1115.0

0

416

679

186

Table 4.3 Summary of the mix design per m3 M20 grade concrete

M30 grade concrete

Cement content

383 kg

Cement content

416 kg

Sand content

700 kg

Sand content

679 kg

Water content

191.6 liters

Water content

186 liters

Coarse aggregates

1103 kg

Coarse aggregates

1115 kg

content Mix proportion

content 1:1.83:2.88


Mix proportion

1:1.43:2.68

Page 34


Chapter 5

EXPERIMENTAL ANALYSIS 5.1. Introduction: In this chapter the test conducted are explained in order to determine the properties of fresh and hardened concrete.

5.2. Tests on fresh concrete: In the present experimental program slump test is carried out to determine the workability of the fresh concrete.

5.2.1. Slump test: Slump test is one of the most widely performed test in order to determine the workability of fresh concrete. Workability of concrete is defined as the degree of ability to flow. Higher the slump value; better is the workability of concrete. Slump cone apparatus is used to determine the slump of the fresh concrete. In this experimental scenario the slump test is conducted for different concrete mixes by varying the proportions of leca and cinder and then the test results are compared for both the grades of concrete.

Fig 5.1.Slump cone test process DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 35


5.3. Tests on hardened concrete: Concrete, after curing is subjected to some tests in order to determine the hardened properties. Some of the tests conducted are as follows: 1. Compression strength test 2. Split tensile test 3. Flexural test

5.3.1. Compression strength test: Compression strength is defined as the maximum capacity of the material to resist the compressive load applied on it. Compression strength is the most important hardened property of concrete, which can be easily determined. In the present experimental program the compression strength for different concrete cubes of size 150x150x150mm are determined for the curing periods of 7days, 14 days and 28 days .

Fig 5.2.Compression testing machine


Page 36


Fig 5.3.Concrete cubes freshly prepared

Fig 5.4.Air dried concrete cubes ready for curing

Fig 5.5.Cubes kept in curing tank for curing DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 37


5.3.2. Split tensile test: Concrete is strong in compression and weak in tension hence determination of tensile strength of concrete is very important to determine the load corresponding to which hardened concrete cracks. Split tensile test are carried out for the cylindrical specimen of 150mm diameter and 300mm height for different curing periods of 7 days, 14 days and 28 days respectively.

Fig5.6. Concrete cylinders freshly prepared.

Fig5.7. Cylinder moulds ready for testing. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 38


Fig5.8 Cracking of Specimen at failure.


Page 39


Fig 5.9 Cylinder after failure(100% leca and 0% cinder proportion).

Fig 5.10 Cylinder after failure(100% cinder and 0% leca proportion) DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 40


5.3.3 Flexural test: Flexural strength is one of the indirect methods of determination of tensile of hardened concrete. The cracking and deflection of concrete depend on flexural strength of concrete. Flexural strength is the measure of resistance of the beam or the slab to the bending effect caused by the external load acting on it. It is generally expressed in the term modulus of rupture. As in case of unreinforced beams (prisms) the specimen moulds used for the flexural test are generally of dimensions 500x100x100mm.

Fig 5.11 Flexural test on concrete prisms


Page 41


Chapter 6

RESULTS AND DISCUSSIONS 6.1. Introduction: In this chapter the test results for both fresh concrete and hardened concrete are tabulated.

6.2. Tests on fresh concrete: In order to determine the workability of fresh concrete, slump test is carried out for M20 and M30 grade conventional as well as the light weight concrete. The results are tabulated as shown in table 6.1 Table 6.1.Slump for M20and M30grade light weight aggregate concrete

Leca (%)

Cinder (%)

Slump values (mm) M20 grade

M30 grade

0

100

34

29

10

90

36

34

20

80

40

37

30

70

51

42

40

60

60

51

50

50

54

47

60

40

49

43

70

30

46

41

80

20

44

37

90

10

41

33

100

0

37

31


Page 42


70 60

SLUMP(MM)

50 40 30 M20

20 10 0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph6.1 Slump values verses aggregate proportion for M20 grade concrete.

60

SLUMP(MM)

50 40 30 M30


Graph6.2 Slump values verses aggregate proportion for M30 grade concrete. The graph 6.1 shows the result of slump test conducted for M20 grade concrete by replacing Leca and cinders in various proportions (Table 6.1) by coarse aggregate. It is observed from the graph that for 0% leca and 100% cinder, the slump value is 34mm. Similarly, for 10% leca and 90% cinder the slump value is 36mm, for 20% leca and 80% cinder slump is 37mm.this trend, .i.e. increase in slump value is observed till the replacement of 40% leca and 60% cinder. After this the slump value is decreasing gradually.i.e. for 40% leca and 60% cinder the DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 43


maximum slump value of 60mm is observed. Whereas for 50% leca and 50% cinder the slump value decreased to 54mm. Similarly for other proportions the slump value is decreased, and same can be observed in the graph 6.1. This may be because, of the presence of clay content in leca absorbs more water from the fresh concrete and therefore decreases in the slump value is observed and increase in the leca proportion decreases the slump value of fresh concrete. Same trend of results is observed even for M30 grade of concrete also. And same is shown in table 6.1 and graph 6.2.The variation of the slump value is in the similar extent as that of M20 grade concrete .i.e. the slump value is found to be comparatively high for 40% replacement of leca and 60% replacement of cinder. 70

SLUMP(MM)

60 50 40 30

M20

20

M30

10 0 0 10 100 90

20 30 40 50 60 70 80 80 70 60 50 40 30 20 AGGREGATE PROPORTION(%)

90 10

100 0

Graph6.3 Comparison of slump values for both M20 and M30 grade concrete w.r.t the aggregate proportion The graph 6.3represents the comparison of the slump values for both M20 and M30 grade concrete with respect to the variation of aggregate proportion. It can be observed that for both M20 and M30 grade concrete the slump value is more for 40% leca and 60% cinder .i.e. 60mm and 80mm respectively compared to other proportions of leca and cinder. It can also be observed that, the value of slump is found to be greater for M20 grade concrete of 60mm when compared to M30 grade concrete of 50mm .This may be due to the reason that as the grade of concrete


Page 44


decreases the water content decreases and the cement content increases which lead to decrease in the value of slump.

6.3. Tests on hardened concrete: The compressive strength, split tensile strength and flexural strength test were conducted for M20 and M30 grade concrete. The results obtained for the curing periods of 7, 14 and 28 days for various proportions are tabulated as shown in the tables.

6.3.1 Compressive strength test: Experiments were conducted to study compressive strength on 150mm cube and same is present and discussed. Table 6.2 Compression test results on M20 grade concrete for 7 days curing period. % of leca

% of cinder

Streng th N/mm

% strength gained wrt NCC

Weight of specimen (kg)

Difference in weight wrt NCC (kg)

Density kg/m3

2

0

100

24.160

95.57

7.692

0.268

2279.11

10 20 30 40 50 60 70 80 90 100

90 80 70 60 50 40 30 20 10 0

23.335 23.056 22.097 21.885 17.856 16.099 14.233 14.152 13.333 13.298

92.31 91.20 87.41 86.57 70.63 63.68 56.30 55.98 52.74 52.60

7.468 7.332 7.269 6.024 5.892 5.734 5.686 5.477 5.144 4.878

0.492 0.628 0.691 1.936 2.068 2.226 2.274 2.483 2.816 3.082

2212.74 2172.44 2153.78 1784.89 1745.78 1698.96 1684.74 1622.81 1524.15 1445.33

For M20 grade concrete of NCC after 7 days of curing period; Strength-25.28 N/mm2 Weight -7.980kg Density-2364.44kg/mm3 DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 45


Table 6.3 Compression test results on M20 grade concrete for 14 days curing period. % of leca

% of

Strength

% strength

Weight of

Difference

cinder

N/mm2

gained wrt

specimen

in weight

NCC

(kg)

wrt NCC

Density kg/m3

(kg) 0

100

28.320

96.82

7.710

0.080

2284.44

10

90

28.000

95.73

7.650

0.385

2266.67

20

80

27.710

94.74

7.500

0.513

2222.22

30

70

27.093

92.62

7.471

0.801

2213.63

40

60

25.040

85.61

6.167

1.833

1827.26

50

50

19.620

67.07

6.090

1.985

1804.44

60

40

19.246

65.79

5.866

2.134

1738.07

70

30

18.312

62.60

5.702

2.298

1689.48

80

20

17.938

61.33

5.499

2.501

1629.33

90

10

16.061

54.91

5.168

2.832

1531.26

100

0

15.696

53.66

4.897

3.103

1450.96

For M20 grade concrete of NCC after 14 days of curing period; Strength-29.25 N/mm2 Weight -8.01kg Density-2373.33kg/mm3 DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 46



% of cinder

Strength N/mm

2

% Strength

Weight of

Difference in

Density

gained wrt

specimen

weight

kg/m3

NCC

(kg)

wrt NCC (kg)

0

100

32.860

98.57

7.750

0.310

2296.29

10

90

32.442

97.33

7.693

0.367

2279.41

20

80

31.080

93.23

7.542

0.518

2234.67

30

70

30.233

90.66

7.504

0.556

2223.41

40

60

29.924

89.76

6.200

1.860

1837.03

50

50

25.875

77.62

6.113

1.947

1811.26

60

40

23.379

70.13

5.887

2.173

1744.29

70

30

22.055

66.15

5.727

2.333

1696.89

80

20

21.491

64.46

5.520

2.540

1635.56

90

10

19.731

59.19

5.190

2.870

1537.78

100

0

19.022

57.06

4.921

3.139

1458.07

For M20 grade concrete of NCC after 28 days of curing period; Strength-33.336N/mm2 Weight -8.06kg Density-2388.15kg/mm3 DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 47


COMPRESSIVE STRENGTH (N/mm2)

35 30 25 20 7 days

15

14 days 10

28 days

5 0 0

10

100 90

20

30

40

50

60

70

80

90 100

80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.4.Comparison of aggregate proportion verses compressive strength for 7, 14 and 28 days for M20 grade concrete. The graph 6.4 shows the result of the compressive strength test conducted for M20 grade concrete by replacing leca and cinder in various proportions by coarse aggregates for 7,14 and 28 days of curing period. It is observed from the graph that for 0% replacement of leca and 100% replacement of cinder, the compressive strength value for 7 days is 24.16N/mm2 for 14days is 28.32N/mm2 and for 28 days is 32.86N/mm2.Similarly for 10% leca and 90 % cinder the compressive strength value for 7 days is 23.335N/mm2, 14days is28.000N/mm2 and for 28 days it is 32.442N/mm2.This trend, .i.e. decrease in compressive strength is observed till the last proportion. It is also observed that, for 0% leca and 100% cinder, the values of compressive strength are found to be increased with respect to increase in the curing period. This may be due to the reason that as the age of concrete increases, the strength of concrete increases. Further it can also be observed that, as the value of compressive strength decreases with the variation of aggregate proportion in a gradual sense. This may be due to the reason that, the cinder is strong enough as it has high specific gravity than that of leca. Hence with the increase in the leca content and decrease in the cinder content will result in decrease in the value of compressive strength of concrete. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 48

EXPERIMENTAL INVESTIGATION ON DEVELOPMENT OF LIGHT WEIGHT CONCRETE BY BLENDING WITH LECA AND CINDER. 2500

DENSITY Kg/m3

2000 1500 7 days 1000

14 days 28 days

500 0 0 10 100 90

20 30 40 50 60 70 80 90 100 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.5 Comparison of aggregate proportion verses density for 7, 14 and 28 days for M20 grade concrete. The graph 6.5 shows the result of the density for M20 grade concrete by replacing leca and cinder in various proportions by coarse aggregates for 7,14 and 28 days of curing period. It is observed from the graph that for 0% replacement of leca and 100% replacement with cinder the density for 7 days is 2279.11kg/m3 for 14days is 2284.44 kg/m3 and for 28 days is 2296.96 kg/m3.Similarly for 10% leca and 90 % cinder the density for 7 days is 2212.74kg/m3 for 14days is 2266.67kg/m3and for 28 days is 2279.41kg/m3.This trend, .i.e. decrease in density is observed till the last proportion. It is observed that the values of density are found to be increased with respect to increase in the curing period. It is also observed from the graph 6.5 that, the value of density is decreased with respect to the variation of the aggregate proportion, this maximum density i.e. observed for 0% leca and 100% cinder and least is observed for 100% leca and 0% cinder which may be due to the reason that, the specific gravity of leca is lesser than that of cinder.


Page 49


Table 6.5 Compression test results on M30 grade concrete for 7 days curing period.

% of leca

% of

Strength

% Strength

Weight of

Difference

Density

cinder

N/mm2

gained wrt

specimen

in weight

kg/m3

NCC

(kg)

wrt NCC (kg)

0

100

28.420

86.43

7.700

0.340

2281.48

10

90

28.233

85.86

7.625

0.415

2259.26

20

80

27.655

84.11

7.578

0.462

2245.33

30

70

27.115

82.47

7.336

0.704

2173.63

40

60

26.287

79.95

6.201

1.839

1837.33

50

50

23.105

70.27

6.159

1.881

1824.89

60

40

22.952

69.80

5.975

2.065

1770.37

70

30

21.267

64.68

5.766

2.274

1708.44

80

20

20.278

61.67

5.532

2.508

1639.11

90

10

19.991

60.79

5.108

2.832

1513.48

100

0

17.067

51.91

4.923

3.117

1458.67

For M30 grade concrete of NCC after 7 days of curing period; Strength-32.88N/mm2 Weight -8.04kg Density-2382.22kg/mm3


Page 50



% of

Strength

% Strength

Weight of

Difference in Density

cinder

N/mm2

gained wrt

specimen

weight wrt

NCC

(kg)

NCC (kg)

kg/m3

0

100

33.150

96.98

7.820

0.275

2317.04

10

90

32.759

95.81

7.800

0.295

2311.11

20

80

32.164

94.07

7.685

0.410

2277.03

30

70

31.211

91.28

7.475

0.620

2214.81

40

60

29.875

87.38

6.300

1.595

1866.67

50

50

26.156

76.50

6.219

1.896

1842.62

60

40

24.842

72.66

5.992

2.103

1775.41

70

30

23.112

67.59

5.802

2.293

1719.11

80

20

22.785

66.64

5.633

2.462

1669.03

90

10

22.231

65.02

5.277

2.818

1563.56

100

0

21.567

63.07

5.168

2.927

1531.26

For M30 grade concrete of NCC after 14 days of curing period; Strength-34.19N/mm2 Weight -8.095kg Density-2398.52kg/mm3


Page 51


Table 6.7 Compression test results on M30 grade concrete for 28days curing period. % of % of cinder Strength leca N/mm2

% Strength

Weight of

Difference in Density

gained

specimen

weightwrt

wrtNCC

(kg)

NCC (kg)

kg/m3

0

100

39.011

97.83

8.000

0.44

2370.40

10

90

38.663

96.96

7.830

0.61

2320.00

20

80

38.586

96.77

7.560

0.88

2240.00

30

70

37.753

94.68

7.450

0.99

2207.40

40

60

37.152

93.17

6.710

1.73

1988.15

50

50

32.875

82.44

6.320

2.12

1872.60

60

40

29.672

74.41

6.000

2.44

1777.78

70

30

27.574

69.15

5.820

2.62

1724.44

80

20

26.870

67.38

5.635

2.81

1669.63

90

10

26.480

66.41

5.332

3.11

1579.85

100

0

25.879

64.90

5.200

3.24

1540.74

For M30 grade concrete of NCC after 28 days of curing period; Strength-39.875N/mm2 Weight -8.440kg Density-2500.74kg/mm3 DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 52


EXPERIMENTAL INVESTIGATION ON DEVELOPMENT OF LIGHT WEIGHT CONCRETE BY BLENDING WITH LECA AND CINDER. 45 40 35 30 25 20 15 10 5 0

7days 14 days 28 days 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.6 Comparison of aggregate proportion verses compressive strength for 7, 14 and 28 days for M30 grade concrete.

2500

DENSITY Kg/m3

2000 1500 7 days

1000

14 days

500

28 days

0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.7Comparison of aggregate proportion verses density for 7, 14 and 28 days for M30 grade concrete. Similarly, the compressive strength test were conducted for M30 grade concrete also for 7,14 and 28 days of curing period, the results are tabulated as shown in table 6.5,6.6 and 6.7.Graph 6.6 shows the compressive strength verses aggregate proportion and graph 6.7 shows the result of density verses aggregate proportion. Further it can be observed that for M30 grade concrete also same trend of results are observed as that of M20 grade concrete and the same is shown in DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 53


graph 6.6 which shows the result of compressive strength verses aggregate proportion.


45 40 35 30 25 20

M20

15

M30


Graph 6.8 Comparison of compressive strength values for M20 and M30 grade concrete for 28 days of curing. Further an attempt is made to study the comparison between M20 and M30 grade concrete for 28 days of curing period. The graph 6.8 shows the compressive strength verses the aggregate proportion for both M20 and M30 grade concrete. From the graph it is observed that the values of the compressive strength are found to be decreased with the variation of the aggregate proportion .That is in both M20 and M30 grade concrete. That is for 0% replacement of leca and 100% replacement of cinder, the value of compressive strength for M20 grade concrete is found to be 32.86N/mm2 and for M30 grade concrete is 39.011N/mm2and with 10% leca and 90% cinder, the compressive strength for M20 grade concrete is 32.442N/mm2and for M30 grade concrete is 38.663N/mm2.It is also observed that, the strength value increases with increase in the grade of concrete. This may be due to the reason that as the grade of concrete increases the strength value is found to be increased.


Page 54


DENSITY Kg/m3

2500 2000 1500 M20

1000

M30

500 0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.9 Comparison of densities for M20 and M30 grade concrete for 28 days of curing. The graph 6.9 shows the variation of the values of density with the variation of the aggregate proportion for both M20 and M30 grade concrete. From the graph it is observed that, the values of the density are found to be decreased with the variation of the aggregate proportion in both M20 and M30 grade of concrete. That is for 0% replacement of leca and 100% replacement of cinder the value of density for M20 grade concrete is found to be 2296.29kg/m3and for M30 grade concrete is 2370.40kg/m3and with 10% leca and 90% cinder the compressive strength forM20 grade concrete is 2279.41kg/m3and for M30 grade concrete is 2320.00kg/m3. With 40% replacement of leca and 60% replacement of cinder the density value for M20 grade of concrete is1837.03kg/m3and forM30 grade of concrete it is 1988.15kg/m3.It can be analyzed that, the strength is considerably decreasing for the variation of aggregate proportions, but has comparatively high density when compared to that of light weight aggregate concrete. But 40% leca and 60% cinder proportion provides low density, compared to other proportions and hence meets the requirements of light weight aggregate concrete.

It is also observed, that the

density value increases with increase in the grade of concrete this may be due to the reason that as the grade of concrete increases the strength is found to be increased.


Page 55


6.3.2. Split tensile test: Here an attempt is made to study the behavior of light weight concrete when it is to the subjected split tensile test for the cylindrical specimen for the curing period of 7 days, 14 days and 28 days for both M20 and M30 grade of concrete. Table 6.8 Split tensile test results on M20 grade concrete for 7 days curing period % of leca

% of

Strength

% strength

Weight of

Difference in

cinder

N/mm2

gained wrt

specimen (kg)

weight wrt

NCC

NCC (kg)

0

100

1.96

89.09

11.62

0.34

10

90

1.88

85.45

11.60

0.36

20

80

1.86

84.54

11.60

0.36

30

70

1.75

79.54

11.58

0.38

40

60

1.69

76.82

11.30

0.66

50

50

1.47

66.82

11.25

0.71

60

40

1.35

61.36

10.95

1.01

70

30

1.15

52.27

10.85

1.11

80

20

0.99

45.00

10.70

1.26

90

10

0.87

39.55

10.67

1.29

100

0

0.85

38.64

10.40

1.56

For M20 grade concrete of NCC after 7 days of curing period; Strength-2.20N/mm2 Weight -11.960kg


Page 56


Table 6.9 Split tensile test results on M20 grade concrete for 14 days curing period % of leca

% of

Strength

% strength

Weight of

Difference

cinder

N/mm2

gained wrt

specimen

in weight

NCC

(kg)

wrt NCC (kg)

0

100

2.42

97.97

11.78

0.22

10

90

2.39

96.76

11.77

0.23

20

80

2.36

95.54

11.74

0.26

30

70

2.30

93.12

11.65

0.35

40

60

2.25

91.09

11.42

0.58

50

50

1.89

76.52

11.35

0.65

60

40

1.75

70.85

11.15

0.85

70

30

1.46

59.11

10.98

1.02

80

20

1.27

51.42

10.85

1.15

90

10

1.11

44.94

10.76

1.24

100

0

1.09

44.13

10.60

1.40



Page 57


Table 6.10 Split tensile test results on M20 grade concrete for 28 days curing period. % of leca

% of

Strength

% strength

Weight of

Difference

cinder

N/mm2

gained wrt

specimen

in weight

NCC

(kg)

wrt NCC (kg)

0

100

2.63

99.24

11.97

0.33

10

90

2.60

98.11

11.90

0.40

20

80

2.58

97.36

11.88

0.42

30

70

2.55

96.22

11.79

0.51

40

60

2.50

94.34

11.55

0.75

50

50

2.09

78.86

11.44

0.86

60

40

1.90

71.69

11.25

1.05

70

30

1.58

59.62

11.05

1.25

80

20

1.37

51.69

10.93

1.37

90

10

1.25

47.16

10.85

1.45

100

0

1.19

44.90

10.72

1.58



Page 58


SPLIT TENSILE STRENGTH (N/mm2)

3

2.5

2

1.5

7 days 14 days

1

28 days

0.5

0 0

10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.10 Comparison of aggregate proportion verses split tensile strength for 7, 14 and 28 days for M20 grade concrete. SPLIT TENSILE STRENGTH (N/mm2)

3 2.5 2 1.5

7 days 14 days

1

28 days 0.5 0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.11 Comparison of aggregate proportion verses split tensile strength for 7, 14 and 28 days for M30 grade concrete.


Page 59


The graph 6.10 shows the results of split tensile strength for 7days, 14 days and 28 days of curing period with respect to the variation in the aggregate proportion for M20 grade of concrete. It can be observed that, strength value increases with respect to increase in curing period. That is with 0% replacement of leca and 100% replacement of cinder the value of split tensile strength for 7 days of curing period is 1.96 N/mm2, where as for 14 days of curing period is 2.42N/mm2 and for 28 days of curing period it is found to be 2.63 N/mm2. It is also observed that, the split tensile strength is found to be varying in a detrimental way with the variation in the aggregate proportion. That is, with 0% replacement of leca and 100% replacement of cinder, the value of split tensile strength for 28 days of curing is found to be 2.63 N/mm2.whereas with 10% replacement of leca and 90% replacement of cinder the value of split tensile strength is found to be 2.60N/mm2.This may be due to the reason that, the specific gravity of leca is less than that of the cinder. Similarly experiments conducted for M30 grade concrete also exhibited same trend of results and the same is shown in graph 6.11.


Page 60


Table 6.11 Split tensile test results on M30 grade concrete for 7 days curing period

% of leca

% of

Strength

% strength

Weight of

Difference

cinder

N/mm2

gained wrt

specimen

in weight

NCC

(kg)

wrt NCC (kg)

0

100

2.13

90.25

11.78

0.20

10

90

2.06

87.28

11.74

0.24

20

80

2.02

85.59

11.66

0.32

30

70

1.90

80.50

11.62

0.36

40

60

1.85

78.38

11.34

0.64

50

50

1.62

68.64

11.20

0.78

60

40

1.49

63.13

11.05

0.93

70

30

1.28

54.23

10.95

1.03

80

20

1.15

48.73

10.82

1.16

90

10

1.07

45.34

10.77

1.21

100

0

0.93

39.41

10.56

1.42



Page 61


Table 6.12 Split tensile test results on M30 grade concrete for 14 days curing period.

% of leca

% of

Strength

% strength

Weight of

Difference

cinder

N/mm2

gained

specimen

in weightwrt

wrtNCC

(kg)

NCC (kg)

0

100

2.60

98.11

11.85

0.21

10

90

2.57

96.98

11.84

0.22

20

80

2.55

96.22

11.81

0.25

30

70

2.50

94.33

11.79

0.27

40

60

2.46

92.83

11.42

0.64

50

50

2.20

83.02

11.26

0.80

60

40

1.97

74.34

11.18

0.88

70

30

1.75

66.04

11.00

1.06

80

20

1.43

53.96

10.90

1.16

90

10

1.35

50.94

10.82

1.24

100

0

1.22

46.04

10.63

1.43



Page 62


Table 6.13 Split tensile test results on M30 grade concrete for 28 days curing period. % of leca

% of

Strength

% strength

Weight of

Difference

cinder

N/mm2

gained

specimen

in weightwrt

wrtNCC

(kg)

NCC (kg)

0

100

2.72

99.27

11.97

0.53

10

90

2.70

98.54

11.96

0.54

20

80

2.67

97.44

11.92

0.58

30

70

2.64

96.35

11.85

0.65

40

60

2.60

94.89

11.51

0.99

50

50

2.36

86.13

11.40

1.10

60

40

2.25

82.12

11.32

1.18

70

30

1.89

68.98

11.25

1.25

80

20

1.52

55.47

10.97

1.53

90

10

1.47

53.65

10.92

1.58

100

0

1.30

47.44

10.88

1.62

For M30 grade concrete of NCC after 28days of curing period; Strength-2.74N/mm2 Weight -12.50kg


Page 63


SPLIT TENSILE STRENGTH (N/mm2)

3 2.5 2 1.5 M20 1

M30

0.5 0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.12 Comparison of split tensile strength values for M20 and M30 grade concrete for 28 days of curing. Graph 6.12 shows the comparative study of split tensile strength of M20 and M30 grade concrete for 28 days of curing period. It is observed that, for all the aggregate proportion the strength of M30 grade performance is better compared to that of M20 grade concrete .This shows that as the grade of concrete increases the strength value also increases.

6.3.3: Flexural strength test: Experiments were also conducted to study the behavior of leca and cinder as coarse aggregate subjected to flexural strength test for M20 and M30 grade concrete for 7 ,14 and 28 days curing period .Same is shown in tables 6.14 and 6.15 and graphs 6.13 and 6.14 respectively.


Page 64


Table 6.14 Flexural strength test results for M20 grade concrete. % of leca

% of cinder

7

days

14 days

28 days

Strength

Strength

Strength

N/mm2

N/mm2

N/mm2

100

3.513

4.088

4.334

10

90

3.479

4.057

4.256

20

80

3.361

4.029

4.185

30

70

3.357

3.969

4.119

40

60

3.185

3.866

4.143

50

50

2.707

3.200

3.482

60

40

2.672

3.159

3.334

70

30

2.585

3.056

3.226

80

20

2.550

3.015

3.181

90

10

2.369

2.800

2.955

100

0

2.333

2.758

2.911

FLEXURAL STRENGTH(N/MM2)

0

5 4 3 7 days

2

14 days

1

28 days

0 0

10 20 30 40 50 60 70 80 90 100

100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.13Comparison of aggregate proportion verses flexural strength for 7, 14 and 28 days for M20grade concrete DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 65



6 5 4 3

7 DAYS 14 days

2

28 days 1 0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.14Comparison of aggregate proportion verses flexural strength for 7, 14 and 28 days for M30 grade concrete. It is observed from the graph 6.13 that, for 0% replacement of leca and 100% replacement of cinder the flexural strength value for 7 days of curing period is

3.513N/mm2,

for 14days

is

4.088N/mm2

and

for

28

days

it

is

4.334N/mm2.Similarly for 10% leca and 90 % cinder the flexural strength value for 7 days of curing period is 3.479N/mm2,for14days is 4.057N/mm2 and for 28 days it is 4.256N/mm2.This shows that decrease in flexural strength is observed till the last proportion that is 100% leca and 0% cinder . It is observed that, the values of flexural strength are found to be increased with respect to increase in the curing period. This may be due to the reason that, as the curing period of concrete increases, the strength also increases. From the graph it is also observed that as the value of flexural strength decreases with the variation of aggregate proportion in a gradual sense, this may be due to the reason that the cinder is strong enough and have high specific gravity when compared to leca. Hence with the increase in the leca content and decrease in the cinder content will result in decrease in the value of flexural strength of concrete. Same trend of results are observed in case of M30 grade concrete also and the same is presented in graph 6.14. DR AMBEDKAR INSTITUTE OF TECHNOLOGY

Page 66


Table 6.15 Flexural strength test results for M30 grade concrete. Leca %

Cinder%

7 days

14 days

28 days

Strength

Strength

Strength

N/mm2

N/mm2

N/mm2

0

100

4.111

4.550

5.032

10

90

4.079

4.515

4.967

20

80

4.043

4.447

4.924

30

70

3.901

4.354

4.871

40

60

3.872

4.245

4.755

50

50

3.581

3.871

4.288

60

40

3.472

3.753

3.985

70

30

3.364

3.636

3.883

80

20

3.292

3.557

3.776

90

10

3.230

3.492

3.711

100

0

3.158

3.414

3.579


Page 67



6 5 4 3 M20

2

M30

1 0 0 10 20 30 40 50 60 70 80 90 100 100 90 80 70 60 50 40 30 20 10 0 AGGREGATE PROPORTION(%)

Graph 6.15 Comparison of aggregate proportion verses flexural strength for M20 and M30 grade concrete for 28 days curing period. The comparative graph of flexural strength verses aggregate proportion for 28 days of curing period for both M20 and M30 grades of concrete are plotted and graph 6.15 represents the same. Flexural strength is found to be decreased with respect variation in the aggregate proportion irrespective of grade of concrete; this may be due to the reason that the increase in percentage of leca content decreases the strength of concrete. It is also observed that as the grade of concrete increases the strength value also increases. M30 grade concrete is showing better performance when compared to M20 grade. From all the three tests it is observed that, for all the aggregate proportion; as the percentage of leca increases and cinder decreases the strength is also decreasing, also as the curing period increases strength is increasing irrespective of the grade of concrete.


Page 68


Chapter 7

CONCLUSIONS Based on the experimental analysis the following conclusions were drawn;  The value of slump is observed to be more for 40% replacement with leca and 60% replacement with cinder for both M20 and M30 grade concrete.  The compression strength values for both M20 and M30 grade of concrete are found to be decreased, with respect to the variation in the aggregate proportion. The amount of strength gained is found to be increased with increase in the curing period of concrete. Maximum strength is observed for 28 days of curing period of 32.86N/mm2 and 39.011 N/mm2for M20 and M30 grade concrete respectively.  The split strength and flexural strength values for both M20 and M30 grade of concrete are found to be decreased with respect to the variation in the aggregate proportion. But increases with respect to age and grade of concrete.  The density and weight of the light weight aggregate concrete is found to be less as and when compared to the normal conventional concrete for both M20 and M30 grade of concrete.  With 40 % replacement of leca and 60% replacement of cinder give a better strength with less weight as compared to that of other aggregate proportions.


Page 69


REFRENCES 1. Ananyasheth,AnirudhGoel

,B.H.

Vekatrampai

(2014)”Properties

of

concrete on replacement of coarse aggregates &cementitious materials with styfoam& rice hush ash respectively”,American Journal of Engineering Research(AJER) ,Vol 03,PP-268-271. 2. AlaettinKılıc¸, Cengiz Duran Atis, ErgulYas, FatihOzcan .―High-strength lightweight concrete made with scoria aggregate containing mineral admixturesˮ. Cement and Concrete Research 33, March 2003, pp. 1595– 1599. 3. Anu joy, Harilal ,Mathews M Paul ,Job Thomas(2013),”Effect of aggregate ratio on strength of cold bonded fly ash aggregate concrete subjected to high temperatures”, American Journal of Engineering Research(AJER),vol02,PP-10-15. 4. PayamShafigh, Mahmoud HassanpourM.S.VahidRazavi and Mohsen Kobraei-“An investigation of the flexural behavior of reinforced lightweight concrete beams”-International Journal of the Physical Sciences,Vol.6 No.10,May2011,pp 2414-2421 5. Q.L.YU, P.Spiesz, h.J.H. Brouwers,(2013)”Development of cement based light weight composites”,Elsevier ,44(2013) 17-29. 6. HarilalB. & JobThomas, (2013)”Concrete made using cold bonded artificial aggregates”, American Journal of Engineering Research(AJER), Vol-1,PP20-25. 7. Khandaker M Anwar,Hossain (2013),”Properties of volcanic pumice based cement & light weight concrete”, Cement& Concrete Research,Vol34(2004), PP-283-291. 8. Radhakrishna,

PrithvirajPadachuri,

Abhishek

P.V.(2011)

―Re-

proportioning of LightWeight Concrete with Pumice as Coarse Aggregate by Law of Mixturesˮ. International Journal of Engineering Sciences Research ISSN: 2230-8504, Vol.2, No.4, pp.281-290.


Page 70


9. N. Siva LingaRao, G. VenkataRamana, V. Bhaskar Desai , B. L. P. Swamy(2011) ―Properties of Light Weight Aggregate Concrete with Cinder and SilicafumeAdmixtureˮInternational journal of Earth Sciences and Engineering, ISSN 0974-5904, Vol. 4, No.6, Oct.2011 , pp.907-912 10. Concrete technology-M.S.SHETTY, schand publications, 24th Edition.

PUBLICATIONS: 1. Nagashree B, Dr. S.Vijaya (2015)-“Development of light weight concrete by blending with leca and cinder” International journal for scientific research and development ISSN:2321 0613,Vol.3, Issue .04,June.2015 2. Nagashree B, Dr. S.Vijaya (2015)-“Experimental study on light weight concrete using leca and cinder” International journal of engineering research and technology ISSN: 2278-0181,Vol. 4, Issue .07,July.2015


Page 71

This is to certify that Nagashree B Has published a research paper entitled Experimental Study on Light Weight Concrete using Leca and Cinder as Coarse Aggregates In IJERT, Volume. 4, Issue. 07 , July - 2015

Registration No: IJERTV4IS070071

Date: 06-07-2015

Chief Editor,IJERT

Dr. Ambedkar Institute of Technology

Dr. Ambedkar Institute of Technology

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