Experimental and numerical study of the performance of geopolymer concrete columns reinforced with BFRP bars subjected to lateral impact loading

Structural columns during their service life may be subjected to lateral impact load. It is therefore imperative to investigate the impact-resistant performance of columns for structural safety. Using geopolymer concrete (GPC) and basalt fibre reinforced polymer (BFRP) bars leads to sustainable and corrosion-resistant durable structures, therefore has great application potential in construction. In the present study, GPC columns reinforced with BFRP bars and steel bars were cast and tested under pendulum impact while their ordinary Portland cement concrete (OPC) counterparts were also prepared and tested for comparison. In addition, a numerical model was developed in LS-DYNA and calibrated against the test results. The test and numerical results showed that concrete columns reinforced with BFRP bars experienced severer damage than those reinforced with steel bars under low impact velocity (e.g. 0–2.71 m/s) due to the lower elastic modulus of BFRP bars. However, under relatively high impact velocity (e.g. 3.15–4.43 m/s), concrete columns reinforced with BFRP bars showed superior impact resistance than those reinforced with steel bars due to the much higher tensile strength of BFRP bars, indicating BFRP bars have potential as an alternative to steel bars for reinforcement to resist large impact loads. Additionally, GPC columns showed similar or even better impact resistance than OPC columns under impact loading, indicating GPC could be a good alternative to OPC in construction of structural columns.