Simulation of Masonry Beams Retrofitted with Engineered Cementitious Composites

A thin layer of ductile fiber-reinforced mortar material referred to as Engineered Cementitious Composites, or ECC has been experimentally investigated as a seismic retrofit for unreinforced masonry infill walls in non-ductile reinforced concrete frames. Compression tests of masonry prisms retrofitted with 13mm of ECC were conducted representing the compression strut of a masonry infill under in-plane lateral loading. Similarly, flexural tests of brick beams using a quarter point bending configuration with the constant moment region intended to approximately represent direct tension (in particular in the ECC), were performed to investigate the response of the tension strut of the masonry infill. In-plane cyclic tests of 1/5 scale non-ductile concrete frames with ECC retrofitted masonry infills using different retrofit techniques were also conducted and the results indicated that the ECC can help keep unreinforced masonry walls intact to large lateral drifts, adding significant ductility to the structural system (Kyriakides & Billington, 2008). Different 2D modeling approaches using the commercial finite-element software DIANA to predict the performance of retrofitted masonry under 4-point bending are investigated and are presented here. This study supports on-going research to develop reliable methodologies for researchers and practitioners to assess the performance of non-ductile concrete unreinforced masonry infilled structures retrofitted with ECC using nonlinear finiteelement analysis.