Abstract
This paper examines the experimental drift response of unreinforced masonry (URM) strengthened with textile-reinforced mortar (TRM) overlays subjected to in-plane lateral cyclic displacements and axial compression. Comparative evaluations are carried out on a set of URM and TRM-strengthened wall counterparts collected from the literature in terms of main kinematics and drift parameters. URM walls include both regular and irregular masonry made of clay bricks or stone units, whilst the TRM incorporates polymeric or natural fibres in lime-based renders, representing material characteristics of various historic structures. The assessments undertaken in this study show that the drift capacity of URM walls is well estimated by code procedures. It is also shown that the double-sided TRM-strengthened walls can fail either in diagonal tension or flexure depending on the detailing and properties of the TRM. In addition to these modes, one-sided TRM-strengthened walls can also develop significant out-of-plane deformations in the post-peak. The ultimate drifts obtained through a bilinearisation procedure vary between 0.66-5.78% depending largely on the strengthening details, overlay thickness and URM compressive strength. The average TRM-strengthened-to-URM ultimate drift capacity ratio of the tests from the literature is 1.75. Although specific expressions to quantify the drift capacity of TRM-strengthened URM members are not available, the current provisions for reinforced masonry are suitable for estimating conservatively the ultimate drift capacity of TRM-strengthened masonry walls.