Development of sandwich panels combining fibre reinforced concrete layers and fibre reinforced polymer connectors. Part I: Conception and pull-out tests

In this paper, an innovative and thermally efficient sandwich panel is proposed for the structural walls of a pre-fabricated modular housing system. Traditionally, sandwich concrete panels consist of reinforced concrete wythes as outer layers, polystyrene foam as core material and steel connectors. However, steel connectors are known to cause thermal bridges on the building envelope, with possible consequent occurrence of condensation and mould problems. Furthermore, the reduction/optimization of the thickness of conventionally reinforced concrete layers is frequently limited by minimum concrete cover requirements for the protection of the reinforcement from corrosion. To overcome these issues, the proposed sandwich panel comprises Glass Fibre Reinforced Polymer (GFRP) connectors and two thin layers of Steel Fibre Reinforced Self-Compacting Concrete (SFRSCC). This paper presents the material and structural concept of the proposed building system. Moreover, the feasibility of using the proposed connectors and SFRSCC on the outer wythes is experimentally investigated through a series of pull-out tests where failure modes and load capacity of the connections are analysed.