Investigation of Crab (Portunus pelagicus) Shells in Concrete as a Potential Substitute for Fine Aggregate

Abstract

Abstract Blue crab shell (Portunus pelagicus) is a fairly abundant domestic waste in the Indo-Pacific and has the potential to be reused. This study aimed to take advantage of the benefit of crab shells, which contain a lot of calcium carbonate and can potentially help the cement hydration reaction to create concrete strength. This study analyzed the mechanical properties of concrete containing crab shell powder (CSP). The composition of crab shell powder as a substitute for fine aggregate (FA) with variations of 5%, 7%, and 8% wt. FA. Crab shells (CS) are dried and finely crushed with a diameter of 1/8 inch, or equivalent to the diameter of FA. This study uses w/c ratios of 0.4 and 0.5 and all aggregates in SSD condition. The results show that the compressive strength of concrete containing CSP is above the strength of the design concrete. The composition of 5% CSP at a w/c ratio of 0.4 is equivalent to the strength of normal concrete with a w/c of 0.5%. The result showed the potential for CSP to replace fine aggregate while helping the cement hydration process.