“…Cockle shell is a by-product or waste from the seafood industry (Zakaria, Mohammad, Hanifah, Kamarudin, & Ahmad, 2021). In the literature review, a few background studies revealed that a high calcium oxide (CaO) level inside the cockle shell causes sluggish hydration, which can lead to reduced concrete strength at an early age but increase at later ages (Murugan, Natarajan, Karthik, & Johnpaul, 2020). Following that, the inclusion of cockle shells in the concrete mixture results in a high initial setting, high density, and good compressive strength.…”