Bond stress–slip constitutive relationship between engineered geopolymer composites (EGC) and rebar under cyclic loading

Abstract

This study investigated the performance of the bonding between engineered geopolymer composites (EGC) and rebar under cyclic loading. A total of 120 specimens were designed for the study. EGC ultimate tensile strain, rebar diameter, and anchorage length were selected as variables, and the bond slip data under cyclic loading were collected using the pull–out method. These variables and data were used to study the failure mode, energy dissipation and bond strength degradation of the specimens. The results showed that the bonding between EGC and rebar is good under cyclic loading, EGC with a high ultimate tensile strain effectively reduce the bond stress degradation. In the range of 0.03% – 6.24%, the higher the EGC ultimate tensile strain is, the stronger the energy dissipation capacity of the sample. Whereas increasing the rebar diameter and anchorage length has a negative impact on bonding. Finally, a slip analysis model was established for the bond stress between EGC and rebar under cyclic loading. The prediction results showed that the proposed model accurately reproduces the bond degradation under cyclic loading.