Effect of prior in-plane damage on the out-of-plane performance of concrete masonry infills

This paper presents results of a study on the out-of-plane behaviour and strength of concrete masonry infills bounded by reinforced concrete (RC) frames with prior in-plane damage. The experimental portion of the study consisted of testing of four physical infilled frame specimens at varying levels of in-plane damage. A finite element (FE) model was concurrently developed and validated using the test results. A parametric study using the model was performed to further study the effect of several influential geometric and material parameters including infill aspect ratio, masonry strength, and slenderness ratio. The correlation between the prior in-plane damage sustained by the infill and its out-of-plane strength as affected by each parameter was discussed in detail. The impact of cyclic vs. monotonic loading was also studied. The efficacy of the existing analytical method for calculating the strength reduction was evaluated using both the experimental and FE results. A new reduction factor equation was proposed and the comparison with the existing analytical method against the available results showed an improvement in providing an estimate of residual out-of-plane strength for infills with prior in-plane damage. © 2020 Elsevier Ltd