Properties of Recycled Coarse Aggregate Concrete Modified by Silica Nanoparticles: A Short Review

Compared to the properties of ordinary concrete, the recycled coarse aggregate concrete exhibits the lower strength and poor durability due to many pores and micro-cracks inside the recycled coarse aggregates and the old mortar attached to the aggregate surface. However, the silica nanoparticles with a high pozzolanic activity, a crystalline nucleation effect and a filling effect plays an important role in the application of modified recycled coarse aggregate concrete. Recent work on the properties of recycled coarse aggregate concrete modified by silica nanoparticles was analyzed in terms of workability, mechanical properties, durability and interfacial structure, etc. The modification mechanism of silica nanoparticles to improve the performance of recycled coarse aggregate concrete was further discussed, thus providing some theoretical and technical supports for the application of silica nanoparticles in the performance improvement of recycled coarse aggregate concrete.