Effect of reinforced concrete confinement on the structural behaviour of AAC masonry walls

Abstract

Confined masonry is widely used in areas subjected to seismic, dynamic, and cyclic actions. Increasingly, confined masonry is also being used outside earthquake-prone regions as an alternative to reinforced masonry, which is reflected in the provisions of Eurocode 6. There is a clear research gap concerning the behaviour of confined masonry under monotonic loading, which significantly hinders the verification of the design provisions regarding detailing requirements and the ultimate limit state [ULS] and serviceability limit state [SLS] conditions. The main objective of this study was to determine the effect of confinement on the load levels causing cracking and failure of the walls and on changes in stiffness. The paper presents the results of full-scale tests of unconfined and reinforced concrete-confined autoclaved aerated concrete (AAC) masonry walls. The walls were subjected to compression and shear loading in a single cycle until failure. The effects of confinement on crack morphology, failure mechanisms, and the anchorage of prefabricated system lintels in the confining reinforced concrete elements were analysed. The results demonstrate that confinement significantly alters the cracking pattern of the walls and can effectively affect the load-bearing capacity of masonry walls subjected to monotonic loading.