Flexural behaviour of ambient cured geopolymer concrete beams reinforced with BFRP bars under static and impact loads

The applications of GeoPolymer Concrete (GPC) with basalt-fiber-reinforced-polymer (BFRP) reinforcements could be alternative for conventional structural designs with Portland Cement Concrete reinforced with steel bars for green and sustainable constructions. Very limited studies, however, have been carried out to investigate the performance of GPC beams reinforced with BFRP bars subjected to static loads, and no study of their performance under impact load is available in open literature yet. In this study, ambient-cured GPC beams reinforced with BFRP bars were tested under static and impact loads. Their damage modes, static and dynamic responses were recorded and analysed. The test results showed that the beams experienced flexural failure mode under static load while combined flexure-shear failure mode was observed under impact load. The impact-loading tested beams were further statically loaded to examine their residual capacities. Additionally, numerical models of the tested GPC beams were developed adopting the commonly used concrete material model *Mat_072R3 (KCC model) in LS-DYNA with modified parameters based on the GPC material testing data. The calibrated numerical model was used for parametric simulations. The results showed that with the increased impact velocity, failure mode of the beam shifted from the flexure-governed to punching-shear-governed along with the rupture of longitudinal BFRP bars.

Automated summary

The study conducted tests on GPC beams reinforced with BFRP bars under static and impact loads, revealing flexural failure mode under static load and combined flexure-shear failure mode under impact load, with additional static loading to examine residual capacities. Numerical models were also developed and used for parametric simulations, demonstrating a shift in failure mode from flexure-governed to punching-shear-governed with increased impact velocity.