Performance of Alkali-Activated Concrete Mixes Incorporating Precious Slag as Fine Aggregate

The current study investigates the performance of precious slag (PS) ball as 100% fine aggregate in alkali-activated slag-fly ash concrete (AASFC) for concrete pavements. PS ball is an industrial product obtained from the iron and steel industry completely replaced by natural sand. As an activator solution, sodium silicate (SS) and sodium hydroxide (SH) were utilized, with SH concentrations of 8 M, 10 M, and 12 M. Different SS/SH ratios (1, 1.5, and 2) were used to make AASFC combinations with a 0.3 alkaline liquid-to-binder ratio. AASFC mixes properties such as mechanical strength and durability properties were studied. The test result revealed incorporation of PS ball to the AASFC mix helps in the development of strength and has a major impact on workability. The compressive, tensile and flexural strength of the material improved with SH and SS concentration due to the increased viscosity of the activator solution. The AASFC mixes with PS ball reported high fatigue cycle than specified in the case of traditional concrete with less resistance towards abrasion; the same has been validated through Weibull distribution analysis. The durability performance of AASFC mixes will be investigated through sorptivity test, evaluation of permeable voids with an acid attack test. The test result indicates SH and SS have a significant role towards acid resistance and capillary action involved in the AASFC mixes.