Out-of-plane monotonic testing and fragility function development of screw and adhesive connections of steel-framed gypsum-board panels

Abstract

Extensive evidence indicates that steel-frame (SF) gypsum-board (GB) partitions are susceptible to seismic damage from very small story drift ratio (SDR) demands, which can lead to significant economic losses, environmental impacts, and downtime in buildings. To mitigate this risk, several innovations have been developed in SF-GB partitions, among which the use of adhesive connections (ACs) recently stands out as a replacement strategy to screw connections (SCs) for attaching GBs to SFs. The use of ACs has shown significant increments in both strength and stiffness of partitions, compared to partitions with SCs. However, the behavior of ACs has been studied mainly under in-plane loads and without a detailed analysis of the use of ACs in the reduction of damage states (DSs) neither the generation of fragility curves. This research presents an experimental study of 36 full-scale SF-GB panels, where the structural behavior under out-of-plane loads of SC-SF-GB and AC-SF-GB panels, as well as other design variables such as GB thickness and type of SF, are assessed and compared in terms of strength, stiffness, and DS evolution. The results of the test campaign show that the mean strength and stiffness of AC-SF-GB panels are 101 % and 47 % higher than those of the SC-SF-GB panels, respectively. In addition, AC-SF-GB panels exhibit a better performance compared to SC-SF-GB panels in terms of DS evolution. The results indicate that the type of connection is a design variable with significant impact on the strength, stiffness, and damage evolution of partitions, over the GB thickness and the type of SF. Finally, the developed fragility functions, which pass the goodness-of-fit tests, confirm the enhanced seismic performance of the AC-GB-SF panels and are a key component to perform future loss estimation studies for building-specific assessments.