Utilising quarry fines and GGBS as cement substitutes in mortar for enhanced performance

• Raise a new method of using solid waste to replace cement in mortar to reduce CO 2 emissions from cement in the construction industry; • The effect of replacing cement in mortar with quarry fines and GGBS on the properties of mortar was studied; • Developed a scheme about using quarry fines and GGBS to replace cement in mortar. Quarry dust is a by-product of crushing, screening, storing, and transporting different types of rocks in the quarry industry. The prior research used quarry fines to replace cement as a cementitious material. However, quarry fines and ground granulated blast furnace slag (GGBS) used together to replace cement have yet to be studied. This study investigates the potential of using quarry fines and ground granulated blast furnace slag (GGBS) as substitutes for cement in mortar mixtures. In this research, quarry fines were ground in the ball milling machine for 90 minutes, and the influence of quarry fines and GGBS as cement substitute material on the performance of mortar, such as mechanical, workability, and durability, and the appropriate proportion is discussed. The fresh, mechanical, and durability properties of blended mortar containing 0% to 40% quarry fines, 10% to 50% GGBS and 50% OPC were evaluated. As a result, improved mechanical properties were observed in mortar with 10% quarry fines and 40% GGBS compared to full OPC mortar at 28 days. The mechanical properties of ternary blended mortar reach the highest when the ratio of QF and GGBS is 1:4. In summary, the mortar containing 40% GGBS and 10% QF pulverized for 90 minutes exhibited optimum performance at 28 days. Using quarry fines in mortar can reduce the use of cement in the mortar and control the emission of CO 2 .