Effect of Partial Replacement of Cement with Fly Ash and Coarse Aggregate with Coconut Shell on properties of concrete Neetesh Kumar Research Scholar Civil Engg. Department M.M.M.U.T. Gorakhpur Abhinav Singh Research Scholar Civil Engg. Department M.M.M.U.T. Gorakhpur Abstract: An effort has been made to study the suitability of replacing the 25% of obtained from N.T.P.C. Tanda Uttar Predesh is common for all mixes with cement and simultaneously by replacing 10%, 20% and 30% of coconut shell as coarse aggregate for concrete of grade M 25. Check strength characteristics such as compressive strength of concrete mix are found for 7 days, 14 days, 28 days of curing period and results are analyzed and compared with the regular (conventional) mix. Test for grade as per specified procedure of IS codes. The materials are proportioned by their weight. The water cement ratio is obtained by conducting workability tests. The results found were comparable with that of conventional mix. The proportion used in this study is 1:1.49:3.03 and water cement ratio is 0.47. Keywords: Coarse aggregate, fine aggregate, coconut shell, compressive strength, concrete,, slump, compaction factor. INTRODUCTION Sustainable materials are currently widely considered and investigated in construction engineering research. Some examples of 72 sustainable research worldwide are the use of recycled concrete aggregates, coal, ground clay brick and pervious paver block system. Further, substantial research work has been conducted on fiber-reinforced concrete which is a concrete primarily made of a mix of hydraulic cement, aggregates, water and reinforcing fibers. The Coconut Shell-cement composite is compatible and no pre-treatment is required. Coconut Shell concrete has better workability because of the smooth surface on one side of the shells. The impact resistance of Coconut Shell concrete is high when compared with conventional concrete. Moisture retaining and water absorbing capacity of Coconut Shell are more compared to conventional aggregate In Asia the construction industry is yet to utilize the advantage of LWC in the construction of high rise structures. Coconut Shell (CS) are not commonly used in the construction industry but are often dumped as agricultural wastes.
The aim of this study is to spread awareness of coconut fibres as a construction material. Typical concrete is a mixture of fine aggregates, coarse aggregates, cement and water. Because of its convenient use, it is not only used in building construction but also in other areas roads, harbors, bridges and many more. The usage of concrete is very wide. It is one of the most important constituent materials. It is comparatively economical, easy to make offers continuity solidity and indeed it lays the role of developing and improving our modern society. Coarse aggregates not only constitute the bulk of concrete but also contribute the most towards its compressive strength through high particle strength and close particle interlock. But, the construction industry worldwide is facing a shortage of this natural resource. The recycling of demolished masonry rubble as coarse aggregate in concrete is an interesting possibility due to its environmental benefits. It is not only a viable alternative to natural coarse aggregate but also solves the major problem of disposal of demolition of waste. Recycling construction and demolition waste into aggregate would ultimately lead to fewer quarries and landfills. DESCRIPTIONS OF MATERIALS The materials used in this experiment were locally available and these were Ordinary Portland Cement (O.P.C), Fly ash as partial replacement of cement, sand as fine aggregate, crushed granite and coconut shell both as coarse aggregate. Potable water was used for mixing and curing. Cement: Ordinary Portland cement 43 grade was used conforming to IS 8112 1989 and physical property was given below: S.N. Physical property Test result 1. Compressive 48.35 Strength(MPa) 2. Fineness 6 3. Specific Gravity 3.06 Fly Ash: The burning of harder, older anthracite and bituminous coal typically produces Class F fly ash. This is pozzolanic in nature, and contains less than 20% lime (CaO). S.N. Physical property Test result 1. Specific Gravity 2.37 2. Bulk Density(kg/m 3 ) 1050 Fine Aggregate: Sand conforming to Zone-III was used as the fine aggregate, as per I.S 383-1970. The sand was air dried and free from any foreign material, earlier than mixing. 73
S.N. Physical property Test result 3. Fineness modulus 2.45 4. Specific Gravity 2.56 5. Bulk Density(kg/m 3 ) 6. Water Absorption 1530-1600 0.80 Coarse Aggregates: Crushed granite was used as coarse aggregate of size 20 mm and 10 mm both. S.N. Physical property Test result 1. Maximum Size 20 (mm) 2. Fineness modulus 7.25 3. Specific Gravity 2.70 4. Bulk Density(kg/m 3 ) 5. Water Absorption 6. Aggregate Crushing Value 7. Aggregate Impact Value 1480-1610 0.12 16.60 11.01 Coconut Shell: In this work coconut shell was used as partial replacement of coarse aggregate which is crushed granite. Coconut shells were unruffled from the local temple after that it was cleaned, sun dried, removed fibers to evaluate its properties. Coconut shell needs no pre treatment, except for water absorption. Coconut shell has very high water 74 absorption. Due to this property, before use coconut shells were soaked in potable water for 24 hours. S.N. Physical property Test result 1. Maximum Size 20 (mm) 2. Fineness modulus 6.48 3. Specific Gravity 1.56 4. Bulk Density(kg/m 3 ) 5. Water Absorption 6. Aggregate Crushing Value 7. Aggregate Impact Value 8. Moisture Content 9. Shell Thickness(mm) Compressive Strength Test 510-600 23 2.49 8.55 4.2 3-6 For compressive strength test cubes of size 150 150 150 mm 3 made. Test was done on the hydraulic testing machine. Compressive strength is defined as resistance of concrete to axial loading. Cubes are put in the machine and after tighten its wheel start button is pressed as pressure is begin to apply. Reading of meter is note down when cracks are there
on cubes. Compressive strength is calculated by following formula: Where P is load and A is area of cube Compressive Strength = P A Fig: Compressive Testing Machine Workability The word workability signifies much wider and deeper meaning than the other terminology consistency often used loosely for workability. Consistency is to indicate the degree of fluidity or degree of mobility. Two tests basically have done for workability namely slump test and compaction factor test with fresh mix. Slump test 75 Collapse: In a collapse slumps the concrete collapses completely. Shear: If one half of the cone slides down then it is called shear slump. True: If concrete slumps evenly it is called true slump. Compaction Factor Test Compacting factor of fresh concrete is done to determine the workability of fresh concrete by compacting factor test as per IS: 1199 1959.
The compaction factor test provides us the CASTING OF CONCRETE CUBES The moulds of size 150 150 150 mm 3 are kept ready before mixing. Total 36 cubes are casted. The bolts of the moulds carefully tightened because if bolts are not kept tight the concrete mixture coming out of the mould when vibration takes place. Then moulds are cleaned and oiled on all contact surfaces of the moulds and place the moulds on vibrating table. The concrete is filled into moulds in layers and then vibrated. The top surface of concrete is struck off level with a trowel. The number and date of casting are put on the top surface of the cubes. TESTS FOR CONCRETE Test for Compressive strength of concrete cubes To calculate the compressive strength of concrete cubes the universal testing machine Days Conventional 10%CS and 25% workability more accurate than slump test (UTM) having capacity of 2000 KN was used. In this test the strength obtained in KN. The measured compressive strength of the specimen shall be calculated by dividing the maximum load applied to the specimen during the test by the cross sectional area calculated from mean dimensions of the section and shall be expressed to the nearest N/mm 2. Compressive strength is defined as resistance of concrete to axial loading. Cubes are put in the machine and after tighten its wheel start button is pressed as pressure is begin to apply. Reading of meter is note down when cracks are there on cubes. Compressive strength is calculated by following formula: Compressive Strength = P A Where P is load and A is area of cube 20%CS and 25% 7 29.78 26.08 24.54 22.89 14 31.56 28.13 26.23 25.36 28 36.44 33.56 32.75 29.39 30%CS and 25% 76
COMPRESSIVE STRENGTH (N/mm 2 ) International Journal of Computer & Mathematical Sciences Fig: Testing of cubes 40 35 30 25 20 15 10 5 0 Compressive Strength Variation with age Conventional0 10% CS, 25% FA 20% CS, 25% FA 30% CS, 25% FA % of replacement with coconut shell and 7 days 14 days 28 days Workability test results S.N Slump (mm) 1 Conventional 84 2 10%CS and 25% 35 3 20%CS and 25% 41 4 30%CS and 25% 47 Compaction Factor 1 Conventional 0.912 2 10%CS and 25% 0.916 3 20%CS and 25% 0.917 77
4 30%CS and 25% CONCLUSIONS 0.922 1. The slump of the concrete increased when the percentage of coconut shell increases and decrease as comparison with the conventional concrete. 2. The compaction factor increased when the percentage of coconut shell increases and increased as comparison with the conventional concrete. 3. The specific gravity of coconut shell is lower than to the coarse aggregate and the water absorption is higher for coconut shell than coarse aggregate so the strength decreased as comparison with the conventional concrete. 4. 25% when replaced with cement and coconut shell as 10%, 20%, and 30% when replaced with coarse aggregate it is found that compressive strength of concrete is lower when compared to conventional concrete. 5. The compressive strength of the cubes reduced as the replacement with coconut shell increased. 6. The cube compressive strength of concrete at the age of 7 days resulted in marginal reduction with 10% and 20% replacement of coarse aggregate with coconut shell. FURTHER SCOPE OF WORK 1. The study can be carried out with varying percentage substitution of the material for specific low cost housing applications. 2. The properties like water absorption, light weight concrete and study on economic aspects can be carried out. 3. The effect of temperature on the concrete developed can be studied. 4. The study can be extended to assess the durability aspects of the concrete with varying replacement proportions. 5. Many other waste materials can be also used in low cost constructions. REFERENCES 1. Dewanshu Ahlawat, L.G.Kalurkar (2013), Strength Properties of Coconut Shell Concrete, International Journal of Civil Engineering and Technology, vol 4, issue 6 Dec 2013 2. Kulkarni V.P, Kumar.S, (2013), Comparitive study on coconut shell aggregate with conventional concrete, Vol.2, Issue 12, pp 67-70 3. Daniel Y.O, (2013), Experimental Assessment on Coconut Shell as 78
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14. I.S 383-1970: Specifications for coarse and fine aggregates 15. I.S 456-2000 Indian Standard: Plain and Reinforced Cement Concrete 16. IS 10262 1982: Recommended guide lines for concrete mix design, Indian standard institution, New Delhi 17. IS 3812-1981: Specifications of for use as a pozzolans and admixture. 18. Mehta P.K., report on High- Performance, High-Volume Fly Ash Concrete for sustainable development, University of California, USA 19. A Report on Use of High-Volume Fly Ash in concrete for Building sector, by Environmental Science & Technology Division, CBRI Roorkee- Jan 2005 20. Kumar Dilip et al, Performance of High Volume Fly Ash in Concrete: A Comparative Study, Innovation in Concrete Construction, Punjab, 2013 80