Rheological and mechanical properties of self-compacting concrete with recycled coarse aggregate from the demolition of large panel system buildings

Self-compacting concrete (SCC), which can be placed and consolidated under its weight without any vibration effort, was first developed in 1988 to achieve durable concrete structures. Since then, a lot of research has been conducted in order to reduce the consumption of raw materials in SCC. Although coarse aggregate and design methods are known to influence concrete properties, there are still knowledge gaps that need to be filled. This study uses a new source of recycled coarse aggregate (RCA), namely the concrete panels of old large panel system buildings demolished in urban areas. The aim of the study is to verify the effect of this aggregate on the rheological and mechanical properties of SCC. To enhance the properties of SCC, the modified equivalent mortar volume (mEMV) method of designing a concrete mix was used. It has not been verified before for SCC, and a literature review suggests it has the potential to eliminate the drawbacks of ordinary equivalent mortar volume methods. The SCC that was used in the study is characterized by having a high viscosity and an average consistency. The hardened SCC used in the research was highly impacted by its mix design and RCA content. Both compressive strength and abrasion resistance decreased when the RCA content increased. However, using the mEMV method resulted in a 10 and 1% improvement in compressive strength and abrasion resistance, respectively.