Axial-flexural behavior of FRP grid-reinforced geopolymer concrete sandwich wall panels enabled with FRP connectors

Abstract

This paper presents experimental and theoretical investigations conducted on a novel precast concrete sandwich wall panel (SWP) subjected to eccentric axial loading. The proposed SWP is composed of geopolymer concrete wythes which were embedded with basalt fiber reinforced polymer (FRP) bars/grids. Hollow Glass FRP (GFRP) tubes were used as connectors. Nine such SWPs were prefabricated and tested. The key design test parameters considered were slenderness ratio of the SWP, load eccentricity, and type of longitudinal reinforcement (FRP bar or grid) in wythes. The failure modes, load-deformation behavior, and load-strain behavior were studied and reported. It was found that the axial load capacities of the eccentrically loaded SWPs subject to load eccentricity-to-sectional thickness ratios of 0.15, 0.45, and 0.63 were reduced by 35%, 75%, and 85% (average of the load capacity values for the slender and squat SWPs), respectively, compared to their counterpart concentrically loaded SWPs. A second-order theoretical analysis was also conducted to obtain the axial load-moment interaction curves of equivalently assumed sections, and the outcomes were compared with the experimental ones to validate the modeling.