Bonding Performance Between Nanomaterial-reinforced Recycled Aggregate Concrete and Rebar

Abstract

Effectively improving the bonding performance of rebar in recycled coarse aggregate concrete is the key to the application of Recycled Aggregate Concrete (RAC) in engineering. This paper aims to improve the mechanical properties of Recycled Coarse Aggregate (RA) by strengthening recycled aggregate with nanomaterials and then improving its bonding performance with rebar. The results show that nanomaterials can fill cracks in aggregates and promote hydration reactions and can reduce the crushing index and water absorption performance of RA by 25.5 % and 14.5 % respectively, increase the compressive performance and splitting tensile performance of RAC by 9.4 % and 13.2 %, and increase the Ultimate Bond Strength (UBS) of RAC and rebar by 12.8 % and 11.2 %, respectively. However, the relationship between the concentration of the nanomaterial solution and the improvement effect is not constant. The concentration of the nanomaterial solution should not exceed a certain range (3 %) to avoid agglomeration of the nanomaterial and improve the effect. In addition, this paper also investigated the strengthening mechanism of nanomaterials and the relationship between nanomaterial-reinforced RA properties, mechanical properties of nanomaterial-reinforced RAC and bonding performance of nanomaterial-reinforced RAC specimens.