Assessment of the Mechanical and Durability Properties of Low-Binder Concretes Produced with Glass Waste

The incorporation of fine powders in concrete, such as supplementary cementitious materials (SCMs), can improve its performance and promote environmental benefits. The use of waste as SCMs in concrete is already widespread, with glass waste being an increasingly used option. The utilization of glass waste as a partial substitute for cement in small proportions has shown satisfactory outcomes. Nevertheless, substituting cement with high volumes of glass powder to produce low-binder concretes requires further investigation. Experimental research was carried out on the mechanical and durability properties of concrete with the replacement of cement by finely ground glass waste (GGW), at a high volume equal to 50%. Compressive strength was evaluated over time. Additionally, water absorption and non-steady-state chloride migration tests were performed. The results indicate satisfactory values of the compressive strength. The specimens with 300 kg/m3 of binder (50% of which was GGW) achieved almost 32.09 MPa at 28 days and 46.42 MPa at 90 days. This result may be related to the high pozzolanic activity index of the used GGW. The specimens with GGW showed greater performance regarding chloride, with diffusion coefficients always below those of the reference specimens. The reduction of porosity provided by the fineness of the GGW may be the main cause of this high performance. The results are promising regarding the use of the high volume of GGW to produce low-binder concretes, with environmental benefits.