Study of arching behaviour and strength of concrete masonry infills under out-of-plane loading
A numerical study using a three-dimensional finite element model was conducted to investigate the arching behaviour and strength of concrete masonry infills bounded by reinforced concrete frames subjected to out-of-plane loading. Physical specimens were concurrently tested to provide results for validation of the model as well as evidence of directional characteristics of arching behaviour of masonry infills. A subsequent parametric study using the model included a wide range of infilled frame geometric properties. The results showed in detail the difference in one-way and two-way arching in terms of both strength and failure mechanism, and the contributing factors to this difference. Evaluation of the two main design equations for out-of-plane strength of masonry infills led to proposal of modifications to provide a more rational consideration of directional behaviour of concrete masonry infills. A comparison study using the available test results showed a marked improvement of strength prediction based on the proposed modification.