The effect of using seashells as cementitious bio-material and granite industrial waste as fine aggregate on mechanical and durability properties of green flowable sand concrete

Abstract

used to replace the natural sand at levels of 0, 10, 20, 30, 40, and 50% by volume, and the SSP has been used to substitute the cement at levels of 5, 10, and 15% by weight. Slump flow and V-funnel flow time tests have been used to investigate the fresh properties of FSC mixtures. Compressive strength, modulus of elasticity, ultrasonic pulse velocity (UPV), water absorption, porosity, and acid attack tests were used to assess the mechanical and durability properties of hardened FSC mixtures. XRD, TGA, and SEM analyses were performed to evolve the microstructure of hardened FSC. The results showed a decrease in the fresh properties of FSC mixtures with the substitution of sand by GW. Nonetheless, the inclusion of SSP as filler mitigated this adverse effect, and all FSC mixes were subsequently discovered to be within the standard limits. The combined use of 50 vol % GW and 10 wt% SSP developed FSC with the greatest compressive strength (67 MPa), modulus of elasticity (40 GPa), and UPV (4175 m/s), as well as the lowest porosity (2.9%) and absorption (2.4%) at 90 days, compared to the control FSC. Moreover, using up to 10 wt% SSP with a fineness of 8000 cm2 /g may enhance the durability of GW-based FSC against acid attack. Microstructural analyses indicated denser microstructure, stronger ITZ, and weaker porosity. The developed eco-friendly FSC effectively showed a decrease in production costs and carbon emissions, reducing the level of waste and protecting natural resources, which provides an emerging approach for its application in advanced green concretes for future work.