Study on coconut shell concrete hollow blocks and the shrinkage, durability and bond properties of mixes used

In this study hollow blocks were produced using coconut shell (CS) as coarse aggregate. For comparison, hollow blocks were also produced with conventional concrete (CC). Mixes were produced both in field and laboratory. Both conventional and CS mixes satisfied the minimum strength required as per IS 2185 (Part 1): 1987. Hollow blocks were tested for their basic properties, shrinkage characteristics, durability properties and bond strength. CS plays a significant role in reducing the shrinkage cracks in the concrete compared with CC constituents. Mixes developed in laboratory displayed better durability properties compared with mixes used in field. Water absorption of hollow blocks was well within the allowable limit of 20%. The experimental bond stresses at 28 days were more than the theoretical bond stress calculated as per BS 8110. This study infers that the use of CS as a potential construction material in the production of hollow blocks is feasible.