The high cost of conventional building materials is a dominant factor affecting the housing system around the world. This has required research work on alternative materials in the field of construction. The conventional coarse aggregate, namely gravel and fine aggregate is sand in concrete, will be used as control. While the natural material is coconut shell as a course aggregate it will be investigated to replace the concrete aggregate. In this study, three different concrete mixtures, namely M20, M35 and M50 will be replaced with different combinations of natural material containing CS in the proportion of 0%, 10%, 20%, 30% and 40%. Six samples will be prepared for each concrete mix. The parameters to be tested are the compressive strength behavior of the specimens of cubes for 7 and 28 days.
A lot of scrap coconut shell is generated in India from the temples and coconut industries and its disposal should be addressed. Researchers have proposed using it as an ingredient in concrete. This experimental research aimed to quantify the effects of partially replacing the coarse aggregate with the coconut shell to produce concrete. The research work was divided into two parts. The first part had as objective to observe the effect of this substitution on the compressive strength and the density of the concrete. In the second part, we tried to find out the additional amount of cement needed to compensate for the reduction of the resistance of the concrete resulting from this substitution. It was found that with an increasing proportion of coconut shells, there is a decrease in the compressive strength. The results revealed that with a 40% substitution of coarse aggregate by the coconut shell, 7 days of compressive strength of concrete decreased by 62.6%; while the 28-day decrease in compressive strength was only 21.5%. The 40% replacement causes the concrete lighter to be 7.47%. In addition, it was revealed that for the concrete mix design of 20 N / mm2 characteristic strength, no additional cement is required for the 5% replacement and only an additional 3.6% of cement is required for the replacement of 10% . The results confirm that while there is an increase in cost due to the need for additional cement, the advantages are many, including efficient use of coconut residue, reduction of natural source depletion, etc., the use of shell coconut in the concrete seems to be a feasible option.