High-volume fly ash self-compacting concrete for coastal constructions: A sustainable development solution

Abstract

This article presents the research results on the effectiveness of applying high-volume fly ash self-compacting concrete (SCC) in constructing environmentally influenced structures along the coast of Vietnam. SCC is designed with fly ash replacing 70% and 80% of cement. Technical criteria evaluated include workability, compressive strength, chloride ion permeability, water absorption, and dry bulk density of SCC. Additionally, the energy consumption, environmental emissions, and production costs of high-volume fly ash SCC are also assessed. The results show that SCC with 70% and 80% fly ash replacement by weight meets construction requirements, with compressive strengths at 28 days reaching 25.1 MPa and 21.2 MPa, and at 90 days reaching 49.4 MPa and 28.3 MPa respectively; chloride ion permeability is very low, electrical resistivity at 28 days is 690C and 539C; water absorption at 28 days is approximately 2.3% and 2.6%; dry bulk density at 28 days is 2239 kg/m³ and 2225 kg/m³. Compared to conventional concrete with equivalent compressive strengths of 20 MPa and 25 MPa (BT200, BT250), using high-volume fly ash SCC with 70% and 80% fly ash replacement results in energy consumption reduction by 45.28% and 53.45% respectively; CO₂, NO_x, SO_x emissions are reduced by (52.41%, 54.26%, 53.95%) and (62.21%, 64.33%, 64.13%); material production costs decrease by 15.14% and 17.16% respectively. Utilizing high-volume fly ash SCC as a solution for coastal constructions proves to be technically feasible, cost-effective, environmentally friendly, and sustainable.