Experimental study on precast concrete sandwich panel with cross-shaped GFRP connectors

Precast concrete sandwich panels (PCSPs) have been extensively used as a facade wall in buildings to improve thermal efficiency. The connectors that link the two concrete wythes are mainly used for in-plane shear transfer. In this study, two cross-shaped glass-fibre-reinforced polymer connectors with different section areas are proposed, with the aim of achieving optimal performance and easy construction in PCSPs. First, the pull-out and shear capacities of the connectors were evaluated. Then four PCSPs and two reinforced concrete solid panel counterparts were fabricated and tested under out-of-plane static loads in order to evaluate their flexural behaviour. The parameters investigated included the connector section area and spacing. Moreover, two-dimensional finite-element (FE) analysis was conducted to reproduce the test. The results indicate that: (a) the proposed connectors can provide considerable performance in terms of anchorage and shear capacity; (b) the failure mode of the PCSP specimens was governed by connector failure; (c) the degree of composite action in terms of ultimate strength can be obviously enhanced by increasing the connector section area and/or reducing its spacing; and (d) based on a comparison with the test results, the proposed FE model can predict the flexural behaviour of the tested PCSPs.