Abstract

A comparison study was conducted on four types of wood and concrete floor systems intended for use in upgrading historic mill buildings. These systems involved various shear fasteners to connect regular strength concrete slabs to the original historic wood decking of the floor system. The approach was intended to provide an increase in strength and stiffness of the floor system, thereby offering a technical solution for common floor performance problems encountered in mill re-use projects. Twenty-five specimens of full-size, wood-concrete composite beams were manufactured and tested to failure in bending. The four connection types considered were: a) nails, b) shear keys with anchors, c) metal plates, and d) a novel connection in which concrete aggregate was embedded into epoxy and then used as the shear connector. Overall, the epoxy-aggregate connection showed the highest stiffness as well as highest strength of all connector types. While the nails had a lower stiffness, their strength was higher than both the metal plate and the shear key connections. All systems outperformed the unconnected control sample both in terms of strength and stiffness, proving that increasing both the strength and stiffness of historic mill floors is possible using a variety of commonly available fasteners.