Development of a finite element model for partially grouted reinforced masonry

Within the Caribbean, the traditional building design consists of a reinforced concrete (RC) moment frame infilled with hollow concrete masonry units (CMU). As a result of growing awareness of the seismic risk in the Caribbean, many engineers have begun to reinforce and partially grout the CMU walls and connect them to the RC frame to prevent them from falling out during a seismic event. This forms a hybrid concrete-masonry structure. Although there is some codified guidance for the assessment of existing structures with unreinforced masonry infills, there are no code procedures for reinforced infill to date. The best currently available method for designing or simulating the behavior of reinforced infill panels under lateral loads is the use of finite element (FE). This paper proposes a FE modeling scheme for the partially grouted reinforced infill used in these hybrid concrete masonry structures. The modeling scheme is validated against cyclic tests of partially grouted reinforced concrete masonry walls and the results from one specimen of the test series is presented here. The cracking pattern in the model is consistent with the experimentally observed failure patterns. The initial stiffness, peak capacity, and post-peak behavior of the finite element model are also in good agreement with the experimental data. The results of this study indicate that the model can successfully capture the main features of the response including the cracking patterns and timing of damages.