Suitability of using mussel shells as partial replacement of aggregates in self-compacting concrete

The handling of mussel shell wastes in coastal regions presents an issue that may be addressed by using mussel shells as a construction material. Shells from waste mussels replace aggregate in concrete, whole or in part. The shells of the mussels are well suited to be incorporated as aggregate into a concrete mix since they are primarily composed of limestone, a substance similar to the other ingredients in concrete. The current study focuses on the suitability of using mussel shells to replace aggregates in self-compacting concrete (SCC). The aggregates were substituted with mussel shells in 5, 10, 15, and 20 percentages. The mixes were initially tested for workability, including slump cone test, L-box test, flow test, and V-funnel test, followed by determining the mechanical behavior, such as flexural strength (FS), compressive strength (CS), and split tensile strength (STS). Also, the microstructural analysis of the mixes was done using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX). The results showed that the concrete's fresh, hardened, and microstructural properties could be improved by substituting aggregates with mussel shells up to 15%. Some prime results of the SCC mix exhibited a slump flow value range of 600-700 mm, a V-funnel flow time of 10-13 sec, an L-box test ratio greater than 0.8, CS of 41.97-52.93 MPa, STS of 3.69-4.18 MPa, and FS of 3.75-4.28 MPa. The study concludes that better-performed SCC can be produced at an optimum dosage of 15% mussel shells to partially replace aggregates.