Behaviour of masonry infills with door openings under sequential in-plane and out-of-plane loading

Abstract

Reinforced concrete (RC) frame structures with masonry infills are common in seismic-prone regions. Masonry infills are activated in in-plane and out-of-plane directions under seismic loading and often damaged during earthquakes. Several recent investigations have shown that the combined effects of in-plane and out-of-plane loads are particularly dangerous for masonry infills. However, most of these studies focused on solid infills, and there is little information about the influence of openings on the seismic performance of infills, even though openings may alter the seismic performance of infilled frames significantly. This paper presents results of two experimental tests carried out on masonry infills with full-height door openings. One was tested under pure out-of-plane load, and the second one with sequential in-plane and out-of-plane loads. Thereafter, results of these two tests are compared with experimental findings obtained from two experimental tests with similar loading protocol conducted on solid masonry infills. Results of the study demonstrate the deteriorating effect of door openings, especially under combined in-plane and out-of-plane loads. The results also highlight a need for practical solutions for damage prevention in both infills with and without openings.