Study of recycled concrete aggregate quality and its relationship with recycled concrete compressive strength using database analysis

This work studies the physical and mechanical properties of recycled concrete aggregate (recycled aggregate from concrete waste) and their influence in structural recycled concrete compressive strength. For said purpose, a database has been developed with the experimental results of 152 works selected from over 250 international references. The processed database results indicate that the most sensitive properties of recycled aggregate quality are density and absorption. Moreover, the study analyses how the recycled aggregate (both percentage and quality) and the mixing procedure (pre-soaking or adding extra water) influence the recycled concrete strength of different categories (high or low water to cement ratios). When recycled aggregate absorption is low (under 5%), pre-soaking or adding extra water to avoid loss in workability will negatively affect concrete strength (due to the bleeding effect), whereas with high water absorption this does not occur and both of the aforementioned correcting methods can be accurately employed.