Experimental characterization of the out-of-plane behaviour of masonry infill walls made of lightweight concrete blocks

• Published in: Engineering structures 2021-10, Vol.244, p.112755, Article 112755
• Main Authors: Agante, Marta, Furtado, André, Rodrigues, Hugo, Arêde, António, Fernandes, Paulo, Varum, Humberto
• Format: Article
• Language: English
• Subjects: Buildings; Casualties; Concrete; Concrete blocks; Concrete construction; Damage assessment; Earthquake damage; Earthquakes; Economic impact; Energy dissipation; Energy efficiency; Experimental testing; Force-displacement; Lightweight concrete blocks; Lightweight concretes; Masonry; Masonry infill walls; Out-of-plane behaviour; Reinforced concrete; Retrofitting; Seismic activity; Thermal energy; Unloading; Walls
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2021.112755

•Out-of-plane tests of infill masonry walls with concrete blocks.•Assessment of the impact of previous damage.•Analysis of the effectiveness of using TRM strengthening to improve the OOP behaviour.•Tested walls results were compared with data available in the literature with different masonry units. 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 undergoing a transformation with the vertical hollow concrete blocks' appearance with high thermal and acoustic demands. However, recent evidence from a strong earthquake shows that the masonry infill walls are quite 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 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, damage evolution and energy dissipation capacity. The test results are compared to assess the previous damage effect and the retrofit technique's effectiveness. A final study is presented concerning the masonry unit and slenderness effect with other literature results.