Microstructural and mechanical characterization of the interface between concrete and chemically reactive enamel (CRE) coated rebar

Abstract

Chemically reactive enamel (CRE) coating is an inorganic coating used for corrosion protection and bond enhancement of steel rebar in reinforced concrete (RC) structures. In this study, the bond behavior of CRE coated deformed rebar in concrete was characterized through pull-out tests. The formation and development of the microstructure at the rebar-concrete interface was characterized using Scanning Electron Microscopy (SEM). The effects of coating type, concrete curing age, and rebar size on the rebar-concrete bond behavior were investigated systematically. In addition, efforts were made to understand the mechanism of using CRE coated rebar to enhance bonding. Based on the above observations, the CRE coating significantly influenced the microstructure at the rebar-concrete interface. The rebar with CRE coating had superior mechanical properties to that with epoxy coating and the uncoated rebar due to the enhanced interfacial transition zone and coating adhesion.