Use of Coconut Shell Ash as Aggregates

Transcription

1 Use of Coconut Shell Ash as Aggregates Lalit Kumar 1, Kamal Kumar Pandey 2, and Sabir Khan 3 1,2,3 (Department of Civil Engineering, JIMS Engineering Management Technical Campus, Greater Noida, U.P., India) Abstract: The effect of coconut shell and its ash has been investigated and the experiments have been done to utilize these waste materials with concrete as a partial replacement for coarse aggregate and cement. The coconut shell in the form of aggregate is a material which can be a substitute for coarse aggregate in concrete. The use of coconut shell can also help in the prevention of environment and the economics related to the construction can also be reduced, it also contributes to the sustainable construction. The coconut shell in the form of ash is a material which can be as a substitute of cement. The research indicates that the materials rich in amorphous silica can be used as partial replacement of cement. Use of such material can lead to increase the compressive and flexural strength. The aim of this study is to determine the suitability of coconut shell ash (CSA) as a partial replacement of cement. The objective includes ascertaining the optimum replacement level of ordinary Portland cement (OPC) with (CSA) that will still give required compressive strength as well as compares the setting time of OPC paste with OPC-CSA paste. The aim of this research is to address the issues related to shortage of conventional material, problem of disposal of waste material and review the work done on the use of waste coconut shell and its ash for the production of concrete, and to spread awareness about the utilization of coconut shell and its ash as a construction material in civil engineering. Keywords: Coconut shell (CS), Coconut shell ash (CSA), Sustainable construction, Amorphous silica, Compressive strength, Setting time, Ordinary Portland cement I. INTRODUCTION Infrastructure development across the world created demand for construction materials. Concrete is the premier civil engineering construction material. Concrete manufacturing involve consumption of ingredients, aggregates, water and admixture. Among all the ingredients, aggregates and cement form the major part. There were many experimental work conducted to improve the properties of the concrete by putting new materials, whether it is natural materials or recycle materials or synthetic materials in the concrete mix. The additional material can be replacing the aggregate, cement or just as additive and one form of the additive is natural material. A large amount of agricultural waste was disposed in most of tropical countries especially in Asia for countries like India, Thailand, Philippine and Malaysia. If the waste cannot be disposed properly it will lead to social and environmental problem. The high cost of conventional building materials is a major factor affecting housing delivery in India. This has necessitated research into alternative materials of construction. There is an increasing interest in what happens to products at the end of their useful lives, so natural materials have an advantage in that they can biodegrade or burnt in a carbon-neutral manner [2]. Natural materials like Coconut Shell is not commonly used in the construction industry but still are often dumped as agricultural wastes. However, with the question for affordable housing system for both the rural and urban population of India and other developing countries, various proposals focusing on cutting down conventional building material costs have been put forward[3]. One of the suggestions in the forefront has been the sourcing, development and use of alternative, non-conventional local construction materials including the possibility of using some agricultural wastes and residues as construction materials. Production of coconut shell Coconut is grown in more than 90 countries. In which,india is the third largest, having cultivation on an area of about 1.8 million hectares for coconut production in the world. Annual production is about 10,560,000 tones Coconut [4]. However, it is also the main contributor to the nation's pollution problem as a solid waste in the form of shells. This waste can be utilized as a substitute for either fine or coarse aggregate or cement in concrete production [5]. S.No Country Coconut Production 2012 In Metric Tonnes % of World Total 1 SRI LANKA t 3.3% 2 BRAZIL t 4.8% 3 INDIA t 17% 4 PHILIPPINES t 26.4% 5 INDONESIA t 30% Table 1.1: Source: Faostat Data, 2014 (Last accessed by top 5 of anything: 2014) [4] Page 15

2 Coconut shells as aggregate Concrete obtained using coconut shell as a coarse aggregate satisfies the minimum requirements for concrete. Coconut shell aggregate resulted in acceptable strength which is required for structural concrete. Coconut shell may present itself as a potential material in the field of construction industries. The coconut shell is compatible with cement and no need to pre-treatment for using it as coarse aggregate. Because of the smooth surface on one side of the shells concrete made with coconut shell presents better workability. Coconut shell concrete shows good impact resistance. As compared to conventional aggregate water absorbing and moisture retaining capacity of coconut shell is high. The presence of sugar in the coconut shell, does not affect the setting and strength of concrete because it is not in a free form. It is found that wood based materials being hard and of organic origin, will not contaminate or leach to produce toxic substances once they are bound in concrete matrix [6] [7] [9]. Coconut shells ash as cement Research indicates that most materials that are in rich can be used in partial replacement of cement. It has also been established that amorphous silica found in some pozzolanic materials which react with lime more readily than those of crystalline form. Use of such pozzolana can lead to increase in compressive and flexural strengths. The raw materials used for the manufacturing of cement consist mainly of lime, silica, alumina, and iron oxide. Generally the chemical analysis of coconut Shell ash reveals that it contains some quantities of these elements. Hence coconut shells ash can be used effectively as a supplementary cementitious material. Table 1.2: Chemical composition of coconut shell ash and cement Ingredients Coconut Shell Ash (%) Cement (%) SiO Al 2 O Fe 2 O CaO MgO MnO Na 2 O K 2 O P 2 O SO LOI Source: Taku J. K, Utsev, J. T. (2008). Coconut Shell Ash As Partial Replacement of Ordinary Portland Cement In Concrete Production. IJSTR vol.1, Issue 8. ISSN Aim The aim of this work is to find Economical and Environmental helpful solution for high cost of concrete and to investigate the use of coconut shell as coarse aggregate in concrete and investigate the strengths of coconut shell concretes at different coconuts shells (CS) replacements and also study the effect on strength of partially replaced concrete by adding plasticizers. In this paper, the effect of coconut shells ash as a replacement of cement in concrete is investigated. The aim of this study is to determine the suitability of coconut shell ash (CSA) for use in partial replacement of cement in concrete production and also study the effect on strength of partially replaced concrete by adding plasticizers. II. EXPERIMENTAL WORK Preparing of specimens of partially replaced coarse aggregates with coconut shells aggregates with or without plasticizer. Without plasticizer M-25 grade of concrete was prepared according to mix ratio of 1:1:2. The coarse aggregates were replaced as 10 %, 15 %, 20% by coconut shells of desired size with water-cement ratio of Moulds are cleaned and oiled to avoid the formation of bond between concrete and iron mould. Place the fresh concrete in mould in 3 layers, tamping each layer with temper 25 times. After placing fresh concrete in cubical moulds, it was allowed to set for 24 hours. After 24 hours, it is taken out from mould sand marked with some permanent identification mark i.e. 1, 2, 3 etc. Cubes are now kept in curing tank for 7 and 28 days. After 7and 28 days, concrete specimens were removed from curing tank to conduct tests on hardened concrete. The compressive strength tests are performed on various concrete cube blocks the average of all samples are calculated for different ratio of replacement cubes sample Page 16

3 With plasticizer M-25 grade of concrete was prepared according to mix ratio of 1:1:2[10]. The coarse aggregates were replaced as 10 %, 15 %, and 20% by coconut shells of desired size with 0.43 W/C ratio. Plasticizer is used in the amount of 0.3% by weight of cement for this testing specimen [8] For preparing the specimens of partially replaced cement with coconut shells ash: M-25 grade of concrete was prepared according to mix ratio of 1:1:2. The cement is replaced as 5%, 10%, and 15% by coconut shell ash of desired size with water-cement ratio of With Plasticizer M-25 grade of concrete was prepared according to mix ratio of 1:1:2[10]. The cement were replaced as 5%, 10%, 15% by coconut shell ash of desired size with water - cement ratio of Plasticizer is used in the amount of 0.3% by weight of cement in this testing specimen [8] Fineness modulus, specific gravity, bulk density, aggregate crushing value, aggregate impact and water absorption are also taken care of both of coarse aggregate and coconut shell. Tests are also conducted for cement and with partial replacement of cement with coconut shell ash for fineness, initial and final setting time and for soundness. III. RESULTS Comparison between the results Bar chart1: Compressive Strength Test of C.S Bar chart2: Compressive Strength Test of C.S with plasticizers Bar chart3: Compressive Strength Test of C.S Ash concrete Page 17

4 Bar chart4: Compressive Strength of C.S ash with plasticizer Discussions 1. The result shows that coconut shell concrete can be even used in high strength applications with replacements within or around 10%and while using plasticizers we can replace the coconut shells upto 20% around. 2. Further we can use higher percentage replacement for non-load bearing structures. 3. However, with the help of water plasticizers admixtures, if the water to cement ratio is reduced to 0.43 then, strength of coconut shells replaced concretes is increased upto20%. 4. The compressive strength of coconut shell ash concrete increased with curing aging, but decrease with increasing the percentage of coconut shell ash. 5. The optimum compressive strength of 21.7 MPa was obtained at 5% replacement at 28 days of curing. 6. The strength of the partially replaced coconut shell ash cubes can be increased upto % by adding plasticizer. 7. There is drastically decrease in the strength of the coconut shell ash cube at replacement of 15% or higher. 8. If 5% coconut shells ash and plasticizers are used in concrete than the compressive strength increases upto 26.6 MPa after 28 days. IV. CONCLUSIONS 1. From the experimental results and discussion, the coconut shell has potential as lightweight aggregate in concrete. 2. Also, using the coconut shell as aggregate in concrete can reduce the material cost in construction because of the low cost and abundant agricultural waste. 3. It is concluded that the Coconut Shells are more suitable as low strength-giving lightweight aggregate when used to replace common coarse aggregate in concrete production. 4. The partial replacement of cement with 5% of coconut shell ash (CSA) in concrete gives an average optimum compressive strength of 21.7 MPa at 28 days. 5. The use of coconut shell ash as a partial replacement of cement produced a cheaper structural lightweight concrete using the optimum compressive strength value specify in the research. 6. Partially replaced cement CSA, using water cement ratio of 0.48 is suitable for construction of light load structures such as floors lintels and low cost housing project. 7. However if 5% of coconut shell ash and plasticizers are used in concrete than the compressive strength increase up to 26.6 MPa after 28 days. And this is suitable for construction of heavy weight structures. V. REFERENCES [1] Taku J. K, Utsev, J.T. (2008). Coconut Shell Ash As Partial Replacement of Ordinary Portland Cement In Concrete Production. IJSTR vol.1, Issue 8.ISSN [2] Abdulfatah Abubakar and Muhammed Saleh Abubakar, Exploratory Study of Coconut Shell as Coarse Aggregate in Concrete, Journal of Engineering & Applied sciences, vol.3, December [3] Amarnath Yerramala Ramachandrudu C, Properties of Concrete with Coconut Shells as Aggregate Replacement, International Journal of Engineering Inventions, vol.1, Issue 6, October 2012 [4] FAOSTAT data, 2014 (last accessed by Top 5 of Anything: January 2014). [5] Exploratory study of Periwinkle shells as coarse aggregate in concrete works,a. P Adewuyi Department of Urban and Civil Engineering, Ibaraki University, Hitachi Japan and T. Adegoke Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria. [6] SitiAminah Bt Tukiman and Sabarudin Bin Mohd Investigation the combination of coconut shell and grained palm kernel to replace aggregate in concrete A technical review National Conference on Postgraduate Research (NCONPGR) 2009, UMP Conference Hall, Malaysia. [7] Amarnath Yerramala Ramachandrudu C, Properties of Concrete with Coconut Shells as Aggregate Replacement, International Journal of Engineering Inventions, vol.1, Issue 6, October [8] M.S SHETTY, Concrete Technology Theory and Practice revised edition 2005, S. Chand Company Limited, New Delhi. Page 18

5 [9] [9] Gopal Charan Behera, Ranjan Kumar Behera, Coconut Shell as Coarse Aggregate International Journal of Engineering Research & Technology (IJERT), vol.2, Issue 6, June [10] [10]. IS: , Recommended Guidelines for Concrete Mix Design. [8]. IS: , Specifications for Coarse and Fine aggregate from natural sources of concrete. Page 19