Numerical Study of Out-of-Plane Behaviour of Timber Retrofitted Masonry Prisms

Abstract

Typical unreinforced masonry (URM) walls have little strength to withstand out-ofplane loads. Under severe out-of-plane loading, URM walls failure is likely to be sudden and severe, producing devastating damages and death. Since out-of-plane failure mode has been identified as the most critical failure mode of URM walls, this study thus focuses only on investigating the out-of-plane behavior of URM wall. This paper presents a small scale testing program to evaluate the out-of-plane load capacity and deformation of masonry prism subjected to out-of-plane loading. This is the first stage of a multiphase experimental and numerical investigation into the possibility of retrofitting URM walls using timber-based panels. In this research, flexural bond strength in form of four-point bending test was obtained from nine different masonry prisms (615 x 215 x 102.5mm), three of which are tested as plain specimens. The remaining 6 specimens were retrofitted with an 18mm thick Oriented Strand Board (OSB) timber panel using two different types of connection (C1: adhesive anchor and C2: mechanical connection). Based on the results of the experimental tests, the out-plane load capacity and displacement of both plain and retrofitted specimens were assessed in order to highlight the performance of the proposed retrofit technique. It was observed that the application of OSB panel at the back of masonry greatly influences the flexural behavior of the test specimens preventing sudden failure of masonry prisms.