Effects of curing temperatures and waste marble aggregates on the properties of geopolymer mortars produced with industrial by-products and waste baked clay powders

This study explores the physical, mechanical, and microstructural properties of geopolymer mortars produced from various waste materials, including fly ash (F), blast furnace slag (S), waste baked clay (WBC), and waste marble. A two-phase process was employed to develop mortars meeting specific performance targets. In the first phase, geopolymer mixes were prepared using powdered precursors derived from industrial by-products and WBC. In the second phase, the effect of replacing river sand with waste marble aggregate at varying levels (25 %, 50 %, and 75 % by weight) was investigated, focusing on mixtures demonstrating superior mechanical strength. Results showed that F-based mortars achieved a maximum compressive strength of 38.2 MPa when cured at 80 °C, while S-based mortars reached 48.5 MPa at 60 °C. The mechanical performance of WBC-based mortars improved with 50 % substitution of F or S. Additionally, incorporating up to 25 % waste marble aggregate in F- or S-based mortars enhanced their strength. This research supports the development of sustainable construction materials by promoting the reuse of WBC, industrial by-products, and waste marble. The proposed method presents a feasible pathway to reduce natural resource consumption and carbon emissions associated with conventional mortar production.