Durability, mechanical, workability, and environmental assessment of self-consolidating concrete containing blast furnace slag and natural zeolite

This study aims to investigate the possibility of using industrial and natural supplementary cementitious materials (SCMs) in self-consolidating concrete (SCC) with lower embodied carbon. Binary and ternary blends of ground granulated blast furnace slag (GGBFS) and natural zeolite (NZ) at higher range replacements of up to 50 wt% of Portland cement (PC) were used. Ten SCC mixtures with various binder compositions were evaluated for workability, compressive strength, and durability properties, as well as corresponding environmental impacts based on life cycle assessment (LCA). A new approach for LCA's functional unit which specifies the required concrete cover and effective height for a beam section was used to include structural design and durability in environmental assessment. Utilizing GGBFS and NZ presents a positive synergistic effect resulting in improved water impermeability, electrical resistivity, and resistance to chloride migration compared to binary blends of GGBFS + PC or NZ + PC. LCA for a service life of 100 years showed the ternary SCC mixture with PC replacements of 10% NZ, and 40% GGBFS could reduce global warming potential by up to 38% compared to the control mixture without SCM. This study concludes that a cleaner SCC with enhanced properties and reduced environmental footprint can be achieved by replacing PC with blends of GGBFS and NZ up to 50 wt%.