A review of quality of recycled aggregate and its effect on durability of recycled aggregate concrete
Daosheng Sun, Shansan Shen, Wei Huang, Kaiwei Liu, Aiguo Wang, Jing Chen
Abstract
Due to their high porosity and many interface transition zones, the low-quality recycled aggregates (RA) used in recycled concrete have a higher permeability than those used in new concrete. This makes it easier for hazardous ions to enter the concrete and increases the permeability. The components of the aggregates, the content of the mortar attached to aggregates, and the original concrete strength all play a role in the recycled aggregate’s quality. The components of recycled aggregate are complex, and the loose porous structure of bricks will increase the amount of water that recycled concrete absorbs. Additionally, external moisture and ions are more likely to reach the core of the concrete, reducing its durability. If more adhesive mortar is attached or if the original concrete’s strength is decreased, recycled concrete may absorb more water. The attached mortar can be filled using slurry soaking, microbial mineralization deposition, carbonization curing, and other methods to strengthen recycled concrete. Finally, this work offers a reference for future research on the use of recycled aggregates in engineering.