Experimental and numerical evaluation of the out-of-plane bending behavior of masonry walls retrofitted by Steel Fiber Reinforced Mortar coating

Abstract

The Out-of-Plane (OP) bending behavior of Un-Reinforced Masonry (URM) walls retrofitted by Steel Fiber Reinforced Mortar (SFRM) coating was investigated by performing in-situ experimental tests on two one-way vertically spanning walls. The latter were part of a full-scale two-story hollow block masonry building provided with seismic floor diaphragms and a 30 mm thick SFRM coating applied only on the external surface of the structure. One of the two test walls was tested under monotonic loading whereas the remaining one was subjected to reverse cyclic loading.Non-linear finite element analyses were performed to simulate the behavior of the specimens. To this end, a plane-stress model based on the smeared crack approach was implemented in the commercial code Diana 10.5. The simulations allowed to predict the response of both the strengthened walls and the un-strengthened (reference) member not included in the experimental campaign.The paper reports the results of the experimental tests including some important considerations on the observed failure mechanisms, the resistance and the displacement capacity of the walls. Moreover, the main results of the numerical simulations are reported and compared with those obtained from the tests in order to get a full comprehension of the different mechanisms affecting the response of the specimens.