03.14: Steel connections with thermal barrier for nearly zero‐energy buildings (NZEB)

Abstract

ABSTRACTThis paper summarises the results of a study assessing the thermal and mechanical performances of two solutions of thermal breaks for external steel structures (balconies, passageways …) attached on a façade with external thermal insulation. The first solution is composed of a PVC plate and an acoustic insulation between the end‐plates of the attached beams and the support (floor slab, concrete wall …). The second one is composed of a PVC plate between a saddle and the support and an acoustic insulation under the beam flange. This solution should be used only in the case of a steel structure with supporting elements (columns, cables…) as it does not transfer bending moments. The thermal performances were evaluated by numerical simulations. They showed a reduction by 30 to 65% of the thermal bridge at the attached steel structure connections. The rate of reduction depends on the configuration of thermal break (thickness of insulation, anchor bolts…). As deformable layers are used, between the steel plates and the facade support, the thermal breaks are unconventional steel connections with mechanical performances to be deeply investigated. Thus, an experimental program including static and cyclic tests is performed on various configurations of end‐plates and saddle with thermal breaks to evaluate their mechanical behaviour considering the stiffness and the resistance.