Structural behaviour of composite prefabricated concrete sandwich panels (PCSP) with pultruded square GFRP tubular connectors subjected to eccentric axial compression is investigated in this study. One PCSP was first tested, and then the validated finite element (FE) model was established by calibrating against the experimental results. The validated FE model was employed to examine the effects of key parameters on the load-bearing capacity and failure of the panels under eccentric load. It was found that the orientation of connectors has a negligible impact on the load-bearing capacity of the panel but significantly affects the failure mode. The increase in eccentricity distance of axial load from 0 to 75 mm significantly reduced the ultimate axial capacity of the panel by 66% and shifted the failure mode from compression failure, characterised by concrete crushing, to a combined compression-bending failure with flexural damage on the outer wythe and concrete crushing at the mid-height of the inner wythe. The rise in concrete strength from 25.5 MPa to 60 MPa substantially improved the load-bearing capacity of the panel by 78%, owing to the higher compression and bending strength of the panel with higher-strength concrete. Furthermore, the load-bearing capacity of the panel increased by 9∼16% when the insulation thickness was increased from 50 mm to 300 mm, due to the higher bending strength and stiffness of the panels with a thicker section. The comparison of the load-bearing capacity of the PCSP and solid reinforced concrete (RC) panels of the same thickness and under the same eccentric load revealed that PCSP has 0∼23% lower load-bearing capacity but 25∼ 67% lesser weight than solid panels. The theoretical model proposed to predict the ultimate strength of the examined PCSPs gave an average ratio of 0.91 with a CoV of 0.06 against FE prediction.
Sah et al. (Thu,) studied this question.