Study on Using Ggbfs and Fly Ash to Improve Workability and Mechanical Properties of Gold Tailing Mortar

This study investigates the effects of ground granulated blast furnace slag (GGBFS) and fly ash (FA) on the workability and mechanical properties of mortars using gold tailing. Mortar mixtures were prepared with water to binder ratio (W/B) of 1.1 and the aggregate component was entirely used with gold tailings. 6 mixtures were designed including: control mixtures (CM) with 100 % cement, 3 mixtures cement was partially replaced with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$20 \%, 30 \%, 40 {\%}$</tex> GGBFS and 2 ternary mixtures of cement- 25 % GGBFS-15% FA and cement20 % GGBFS- 10 % FA. The results showed that the flowability of the 25 % GGBFS-15% FA mixture was significantly improved compared to CM.. The mixtures incorporating only GGBFS exhibited the highest density, while the control mix showed the lowest. Compressive strength, flexural strength, ultrasonic pulse velocity of the mixtures improved with increasing GGBFS content, reaching optimal performance at 40% GGBFS replacement. The mixture using 20% GGBFS and 10% FA had compressive strength, flexural strength and ultrasonic pulse velocity approximately equal to the mixture using 40 % GGBFS, showing the combined effect of GGBFS and FA in improving the properties of mortar.