Durability of coconut shell concrete with silica fume

Concrete is the most widely utilised construction material for construction. The largest portion of the volume in concrete comes from the coarse and fine aggregate. The constant removal of aggregates from natural sources has raised their cost and accelerated resource depletion. This study proposes the use of crushed coconut shells and silica fumes as replacements for aggregate and cement, respectively, to address the shortage of aggregate and the decarbonization of the environment. This study investigates the mechanical properties, durability (initial surface water absorption and carbonation resistance), and interfacial transition zone through microscopic examination of coconut shell concrete with 10% silica fume as a cement replacement, A microscopic examination was conducted to observe the bond between cement paste and coconut shells. 10% of silica fume as cement replacement has improved the strength of coconut shell concrete up to 20.3 N/mm². The durability of coconut shell concrete with silica fume is more reliable than coconut shell concrete itself since the coconut shell concrete has been filled with silica fume particles. Therefore, it was demonstrated that coconut shell concrete mixed with silica fume is an acceptable substitution for concrete.