PERFORMANCE ASSESSMENT OF COCONUT SHELL ASH AS PARTIAL REPLACEMENT OF CEMENT IN COMPRESSED EARTH BLOCKS
Earth construction represents the oldest recognized building technique employed by humanity. However, the poor strength and durability of earth blocks limit their use in construction. The two most widely utilized binders to improve the characteristics of these blocks are cement and lime but these are expensive and sources of CO2 emissions. The objective of this study was to assess the performance of coconut shell ash (CSA) as partial replacement of cement in compressed earth blocks (CEBs). The microstructure test was conducted on laterite soil, cement and CSA samples and the blocks were tested in terms of dry density, water absorption and compressive strength at 7, 14 and 28 days. The blocks were stabilized with various cement content from 0 to 8%. After testing blocks with 6% cement showed good performances taken into account the economic aspect. The substitute of cement was carried out by replacing the optimum 6% cement with 2%, 4% and 6% of coconut shell ash (CSA). CSA has improved the dry density, water absorption and compressive strength of CEBs. The highest strength was recorded for blocks stabilized with 4%C+2%CSA at 28 days. Based on the results of this study, an optimum of 2%CSA can be recommended as substitute for cement in making CEBs.
Dry Density; Compressed Earth Blocks; Compressive Strength; Coconut Shell Ash; Water Absorption.