The effectiveness of waste oyster shells (WOS) as major fine aggregate replacement in concrete

Over-exploitation of natural river sand and waste oyster shells (WOS) dumped randomly will cause serious environmental issues. Thus, a drive to using crushed WOS as fine aggregates to substitute river sand in concrete production has been initiated. This paper conducted experimental research to study the possibility of employing the crushed WOS as 100% fine aggregates in concrete. The workability, compressive strength and its size-effect, and sustainability performance of the concrete mixtures were investigated. The results indicated that, under the same water-cement ratio, the WOS concrete showed a great improvement in strength properties while a decline was found in slump tests, compared to the control concrete. Besides, the use of the crushed WOS in concrete production resulted in a modification in both eco-efficiency and cost-efficiency.