Experimental Investigation on Durability Performance of Recycled Aggregate Concrete with Mineral Admixtures

The adhesion of cement mortar and the negative influence of the previous interfacial transition zone (ITZ) on reinforced RAC were the main contributors to the durability of reinforcement. For various replacement amounts of recycled concrete aggregate (RCA), the influence of the inclusion of a mineral additive on the durability performance of RAC was investigated. 25% of ground granulated blast furnace slag (GGBS) and 10% of silica fume (SF) have been used as mineral admixtures. In this work, an experimental investigation was conducted to determine the effects of SF and GGBS combination on RAC with 0%, 25%, 50%, 75%, and 100% RCA. Durability characteristics, water absorption, sorptivity, sulphate attack, acid attack, and thermal resistance were taken. The homogeneity of RAC was also examined using an ultrasonic pulse velocity (UPV) test. The strength is gradually increased by the addition of GGBS, which forms a secondary C-S-H gel and has a lower heat of hydration. The mineral admixture lowers the amount of calcium hydroxide and delays the development of ettringite. Therefore, the addition of a mineral