Proposed new dry and hybrid concrete joints with GFRP bolts and GFRP reinforcement under cyclic loading: Testing and analysis

Abstract

This study proposes a new hybrid concrete joint using glass fibre reinforced polymer (GFRP) bolts and reinforcements to replace steel bolts and reinforcements for corrosion damage mitigation. The experimental results indicate that the proposed hybrid concrete joints satisfy the seismic-resistant requirements with respect to the ductility and energy dissipation. The energy dissipation of the hybrid concrete joint was approximately 57% higher than the reference monolithic joint. In addition, the application of GFRP bolts and reinforcements not only avoided brittle failure during the test but also showed excellent behaviours in terms of the drift ratio, ductility, and energy dissipation. Numerical simulation using ABAQUS software was also carried out, which successfully captured the failure modes, drift ratios, and peak loads of the dry, hybrid, and monolithic joints. The numerical results proved that the common assumptions which were adopted in the proposed models of the previous studies (Ngo et al., 2020; Ngo et al., 2020) [1,2] were reliable to predict the peak loads. The ratio of the thickness of the concrete-end-plate (CEP) over the height of the beam of 1.3 was the optimal value and it can be used in CEP design of the dry joint. Finally, the developed three-dimensional finite element (3D-FE) model verified with the testing data can be confidently applied in future studies to investigate the seismic performances of the dry, hybrid, and monolithic beam-column joints using GFRP reinforcements and bolts.