Pulverized blue swimming crab shell utilized as partial replacement for sand in concrete mixture

Abstract

Problems in the construction today include the overexploitation of natural aggregates as well as corrosion of steel reinforcement. Studies are needed to explore alternative materials that can be used in lieu of natural aggregates. This study investigates the use of pulverized crab shell (PCS) for partial replacement of sand in concrete mixture. The properties of conventional concrete mix are compared with concrete mix with its sand replaced with 10% and 15% PCS. Properties evaluated include compressive strength and splitting tensile strength. The sodium chloride penetration in concrete with PCS is also evaluated. Analysis of variance (ANOVA) was also used to determine if there is any statistical difference among the means of samples compared. The results show that the conventional concrete mix obtained the highest compressive strength and splitting tensile strength, while showing the lowest sodium chloride penetration resistance. The concrete mix with 15% of sand replaced by PCS showed the highest chloride penetration resistance. Although the incorporation of PCS in concrete reduced the compressive strength and split tensile strength in concrete mix, this has potential for use in plastering structures near coastal areas. This is to increase resistance to penetration of chloride in concrete structures which may accelerate deterioration of steel reinforcements that has always been a problem in coastal areas. For further tests, it is recommended that before using PCS in concrete, it should be oven dried or treated and prepared for better fineness and quality. In addition, investigating the potential of heating powdered PCS for cement replacement can be a subject for future research.