Shear Transfer Mechanism Of FRP Connectors In Precast Concrete Sandwich Wall Panels

Precast concrete sandwich wall panels have typically been used for the construction of building envelopes for a wide variety of structures.The panels consist of two discrete layers of concrete panels separated by a rigid foam layer.Panels provide a host of functions,including providing the building envelope,carrying gravity and wind loads,as well as insulating.The shear connectors,transfer the shear forces between the two separated concrete wythes,is essential in attaining composite action.Traditionally,a wide variety of steel connectors have been used to accomplish this transfer of shear forces.T his method,though shown to function well,create thermal bridges across the insulating layer and severely hinder the insulating value of the entire building.Fiber Reinforced Polymer(FRP)material has a significantly lower thermal conductivity in comparison to steel,having been accepted as an alternative construction material for several civil engineering applications.The motivation for the use of these materials is in their ability to provide composite action between the two concrete wythes,allowing for greater structural capacity,higher thermal efficiency,and a longer service life.The research program investigated the effect of several parameters believed to affect the shear flow strength of the CFRP grid(CGRID)/foam insulation material mechanism,including the type of rigid insulating foam,the spacing between rows of CFRP grids,and the angle between CGRID and axis of panel.Finite element analysis conducted to determine the characteristics of the shear transfer mechanism of the grid/insulation.Design equations are created to estimate the shear flow strength and shear modulus for CGRID/rigid foam system as affected by these parameters.