Sensitivity of the bond strength to the structure of the interface between reinforcement and cement, and the variability of this structure

The variability in interfacial structure and the sensitivity of the bond strength to this variation were studied for each of the interfaces between carbon fiber and cement paste, between stainless steel fiber and cement paste, and between steel rebar and concrete. The interfacial structural variation was indicated by the variation in the contact electrical resistivity. The interface between steel rebar and concrete had least variability but most sensitivity. The interface between carbon fiber and cement pastehad less variability but more sensitivity than that between steel fiber and cement paste.