EXPERIMENTAL STUDY ON PERFORMANCE OF RECYCLED AGGREGATE CONCRETE: EFFECT OF REACTIVE MINERAL ADMIXTURES

This paper presents an experimental study on the performance of recycled aggregate concrete (RAC) that includes recycled coarse aggregate (RCA). This study investigates the effect of replacing the natural coarse aggregate (NCA) with recycled coarse aggregate (RCA) on the workability and mechanical properties of concrete. The effect of using reactive mineral admixtures such as fly ash (FA) and silica fume (SF) as cement replacement on these properties of RAC is also examined and compared to the results of natural aggregate concrete (NAC). The mechanical properties include: compressive strength, tensile strength and flexural strength. Various reactive mineral admixtures replacement ratios were used including (20% FA or 20% SF or a combination of 10% FA + 10% SF). In total, five mixes were investigated. The results show that reactive mineral admixtures do not have negative effect on the workability of the RAC. Also, SF leads to better strength improvement of RAC than FA. The combination of both SF and FA can enhance the strength of RAC