Mechanical and fire tests on thermal breaks attached to concrete supports

Abstract

This paper deals with the mechanical and fire behaviour of simple solutions of thermal breaks for external steel structures (balconies, passageways, solar panels …) attached on a concrete facade with external thermal insulation. The proposed solutions are composed of a PVC or plywood layer implemented between an extended end-plate connection and the concrete support (lintel, floor slab, concrete wall). A total of 12 monotonic mechanical tests have been performed on steel-to-concrete connections using intermediate insulation layers (PVC or plywood) in order to investigate the rotational stiffness, plastic/ultimate bending moments, the rotation capacity as well as the failure mode. Two types of fastening were used; bolted embedded end-plates and post-installed mechanical/chemical fasteners. In order to evaluate the influence of the studied solutions of thermal breaks on the behaviour of a balcony under fire, two external flame experimental tests were carried out on realistic balconies attached to a concrete support. These fire tests demonstrated that the implementation of the proposed thermal breaks between end-plates and the support does not affect the stability of the balconies subjected to fire.