The mechanical and durability indices for mortar containing crushed waste oyster shells

Abstract

To better assess the safety of cementitious materials containing crushed waste oyster shells (WOS), the workability, mechanical properties (compressive strength and static elastic modulus) and durability (volume of permeable void (VPV), water absorption (WA) and total charge passed) were studied. The effects of replacing river sand with different content of crushed WOS (0, 10, 20 and 30%) on flowability, mechanical properties and durability of mortar have been revealed. The results indicated that the addition of WOS had a significant effect on the flow table of the mortar, and the loss ratio of FT varied from 25% to 39% at 120 min. Although the compressive strength (fc), static elastic modulus (Ec) and apparent density gradually decreased with the increase of WOS content, the mechanical properties were improved by prolonging the curing time. The incorporation of crushed WOS in mortar increased the VPV and WA, as well as the transport properties of mortar. The replacement of natural river sand with crushed WOS greatly increased the drying shrinkage of mortar. The substituted ratio–Gardner model exhibited the best accuracy in predicting the drying shrinkage development of crushed WOS mortar.

Desenvolvimento e caracterização de concreto sustentável com resíduos de conchas marinhas

“…Em adições no concreto, Kong et al (2022) reportaram que a substituição de concha de ostras pelo agregado natural é viável e pode aumentar a resistência à compressão em teores de até 20% em relação ao agregado miúdo. De forma similar, Liao et al (2022) através de propriedades mecânicas e de durabilidade, recomendam o uso desse resíduo como substituinte da areia de rio em argamassas nos teores de 10 a 30%. Diante desse cenário, o objetivo desse trabalho é investigar a viabilidade do uso de conchas marinhas trituradas como substituinte do agregado miúdo no concreto ecológico.…”