High-volume glass powder concrete as a sustainable and chloride-resistant alternative to fly ash

Abstract

The use of supplementary cementitious materials (SCM) can enhance concrete durability. Fly ash (FA) has been used as SCM, especially in chloride-rich environments, but its availability is decreasing due to the closure of coal-fired power plants in EU countries such as Portugal. Glass powder (GP) emerges as a promising alternative because of its suitable chemical composition and wide availability. To evaluate concrete performance with high GP incorporation, specimens with different binder contents were produced using 50 % of SCM, either FA or GP. Mechanical and durability properties were evaluated, besides their environmental impact. Results showed that concretes with high GP incorporation are chloride-resistant and can be a potential substitute for FA. GP250-50, using 250 kg/m3 of cement, had lower chloride diffusion coefficients than the reference and FA concretes. At 90 days, the reduction was 91 % and 35 %, respectively. Furthermore, they had a significant CO₂ emission reduction (16 %), confirming their sustainable potential.