Impact Response of Prestressed Prefabricated Segmental and Monolithic Basalt-FRP-Reinforced Geopolymer Concrete Beams

The use of low-emission geopolymer concrete (GPC) and noncorrodible basalt-fiber-reinforced polymer (BFRP) bars is an effective strategy in the bid for net zero emissions and making sustainable and durable structures. To date, however, there have been no studies on the impact response of prefabricated/precast segmental concrete beams (PSCBs) constructed using GPC and BFRP bars. This experimental study, therefore, was intended to partially fill this knowledge gap. The key objectives were to investigate the impact behavior of the segmental versus traditional monolithic beams, the effect of impact location, and the performance of GPC versus ordinary Portland cement (OPC) concrete beams. The test results showed that, with the energy absorption capability derived from the opening and sliding of joints, the PSCB experienced less damage than its monolithic counterpart under similar impact conditions. The joints, however, reduced the global stiffness of the PSCB, resulting in the PSCB having a higher displacement, lower impact and reaction forces, but a longer impact force duration and greater impulse, compared to the corresponding monolithic beam. Under the impact loads, the PSCB had a higher tendon force but smaller reinforcement strain than the monolithic beam. Impacting at the joints mobilized the energy absorption capability more effectively, resulting in a reduction in impact-induced damage. The impact performance of both the monolithic and segmental GPC beams was quite similar to that of their OPC counterparts. Thus, GPC can be adopted as a sustainable alternative to OPC in the construction of concrete structures against impact loads. In this study, a three-dimensional finite-element model was also developed in order to obtain a better understanding of the impact behavior of segmental and monolithic beams.