An evaluation of the recycled aggregate characteristics and the recycled aggregate concrete mechanical properties

The difference between the properties of recycled aggregate (RA) and natural aggregate (NA) are caused due to the old mortar attached to RA. In this review, the quantitative relationships were represented about the content of old attached mortar and the performance of RA at the material level. In term of the component level, the influence of replacement ratio of RA on the mechanical properties of concrete was summarized. Finally, some researches have focused on ways to improve the properties of aggregate. The results show that the method of stripping old mortar to improve the performance of recycled aggregates was not the only way to promote the application of recycled aggregates. However, by evaluating some simple and economical methods such as controlling the water-cement ratio, adjusting the aggregate moisture content and the different mixing method can improve the performance of recycled concrete in order to meet the requirement of concrete quality. Three aspects of the performance prediction, application range and reinforcement method for RAs were illustrated in the article. It was believe that the results could promote the accurate application for RAs with different quality in engineering, thus the application range of RAs was expanded.