Flexural Behaviors of Concrete/EPS‐Foam/Glass‐Fiber Composite Sandwich Panel

Abstract

Composite structural insulated panels (CSIPs) have been developed for structural floor applications instead of traditional structural insulated panels (SIPs). However, the load bearing capacity of CSIPs is low due to the debonding between the top face sheet and the core when they are used for floors. To overcome this drawback, an improved composite structural insulated panel (ICSIP) was proposed and analyzed in this paper. In ICSIPs, a thick layer of concrete is used as the top face sheet instead of glass-fiber-reinforced polymer (GFRP) in CSIPs to increase the stiffness of the top compression face sheet. However, the bottom GFRP face sheet and EPS cores in CSIPs are preserved to reduce the weight of the structure and act as a template for the top concrete panels. Full-scale experimental testing and finite-element analysis were conducted to predict the flexural strength and deflection of the ICSIP floor member. Good agreement has been observed between the numerical results and experimental response up to the failure. The cause of failure of ICSIPs is the crushing of concrete face sheet rather than debonding. Moreover, the calculation formula for the ultimate bearing load and deflection was also developed based on the classical sandwich theory. The theoretical predictions reflect well the linear flexural response of the ICSIPs, while deviate as the load increases up to failure due to the theory limitations.

A nonlinear beam-spring-beam element for modelling the flexural behaviour of a timber-concrete sandwich panel with a cellular core

“…A recent study on timber-concrete floor panels with a cellular core structure subjected to flexural loading showed significant transverse shear deformations between concrete and timber layers [13]. Similar behaviour was also commonly observed in other sandwich structures, especially those with an interlayer with a low stiffness [15,16,19]. In addition, such panels also show a clear change in the strain distribution gradient across the thickness of the panel at the face panel-core interface.…”

“…Attempts have been made to reduce the weight of the timber-concrete composite panels by introducing a lightweight interlayer, also referred to as a "core", between the concrete and timber [12,13], thus transforming the composite panel into a sandwich panel system. The interlayer of sandwich panels can be a solid, a porous foam or a cellular structure [14][15][16][17][18][19]. Considering the similarity of the composite floor panels with an interlayer and sandwich panels in flexural behaviour, both structural systems are called "sandwich panels" hereafter.…”

Flexural Deformation of Expanded Polystyrene Concrete Sandwich Beam: An Experimental Study

“…Instead of the EPS concrete sandwich can transfer load and insulate structure perfectly, it has low compressive strength as about less than 10 MPa. Several researches have been carried out to develop EPS and other materials for concrete sandwich structures such as [5][6][7][8][9][10][11][12][13].…”