Development of GFRP-reinforced GFRC for thin permanent formwork applications

A major impediment for the development of precast concrete permanent formwork and other thin structural elements such as cladding is the minimum cover requirement to the reinforcement. For aggressive environments, this can be up to 50 mm, which results in minimum 100 mm thickness units. Currently, glass-fibre-reinforced concrete or cement (GFRC) is used to address that problem in small non-structural elements. However, the structural capacity of GFRC is limited and fibre-reinforced plastic (FRP) reinforcement can be used to structurally reinforce GFRC to enable the development of much larger units. The ‘skin and rib' concept for the design of such units has been developed by the authors and has been used for the design of precast units. The main issues relating to GFRP-reinforced GFRC are bond, anchoring, tension stiffening, deflections and shear capacity of thin panels. This paper presents experimental and analytical work undertaken to address all the above issues. Pull-out tests confirm that the pull-ou...