Adhesively bonded modular GFRP web–flange sandwich for building floor construction

An adhesively bonded modular GFRP sandwich system for use in building floor construction is described in this paper. Sandwich units are formed by incorporating standard pultruded GFRP box or I-profiles between two GFRP flat panels to form built-up modular sections with considerable improvement of bending stiffness. These modular sections can then be assembled in the transverse direction to form a one-way spanning slab system. Sandwich specimens with different span-to-depth ratios and core configurations were prepared via adhesively bonding the component profiles, and were then tested under four-point bending. It was found that the span-to-depth ratio greatly influenced the failure mode, and that inserting foam into the core of the sandwich significantly improved the load-carrying capacity. Also, adhesive bonding was able to provide full composite action at both serviceability and ultimate loads, depending on the quality of the bond. Finally, existing theory was used to estimate the bending stiffness and load-carrying capacity of the sandwich specimens and good agreement with the experimental results was found.