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.QREN-ADI and Fundação para a Ciência e a Tecnologia (FCT)This work is part of the research project QREN number 5387, LEGOUSE, involving the companies Mota-Engil, CiviTest, the ISISE/University of Minho and PIEP. The first author would like to thank the FCT for the financial support through the PhD Grant SFRH/BD/64415/2009. The authors also thank the collaboration of the following companies: Maccaferri and RADMIX™ for supplying the fibres, Secil and SIKA for providing the cement and the superplasticizers, respectively, and S&P – Clever Reinforcement Ibérica for supplying the epoxy adhesive