Out-of-plane testing of masonry infill walls made with lightweight concrete blocks

Abstract

The masonry infill walls are widely spread over the reinforced concrete buildings due to different demands. The buildings' thermal energy efficiency is a top priority nowadays since many of the existing building stock comprises buildings with low energy performance. The buildings' external envelope is suffering a transformation with the appearance of the vertical hollow concrete blocks with high thermal and acoustic demands. However, recent evidence from a strong earthquake shows that the masonry infill walls are vulnerable to out-of-plane loadings and were responsible for many casualties, injuries, and economic losses. Based on that, this work's main objective is to study the out-of-plane (OOP) behaviour of masonry infills made with vertical hollow concrete blocks. The experimental campaign comprises the OOP testing of three full-scale infill walls made up of these masonry units. One of them was as-built without previous damage, one with previous damage due to an earlier in-plane test and the third one retrofitted. All the tests consisted of applying the loading-unloading-reloading history of imposed displacements in the OOP direction through a uniformly distributed load. The results will be presented in terms of OOP force-displacement responses, deformed shapes, damage evolution, energy dissipation capacity and damping. Finally, the test results are compared to each other to assess the previous damage and the retrofit technique's effectiveness.