All over the world, reinforced concrete is used in building construction and earthquake prone countries like El Salvador are not exception. Understanding the behavior of this kind of structures when subjected to seismic loads is of great value. In 2011, the Tohoku Earthquake left lightly reinforced concrete walls of many residential facilities and governmental buildings severely damaged, up to the point that the structures were demolished as the cost of repair was uneconomical. In addition, understanding of this kind of walls is limited, and further research is necessary.
In this thesis, a study of failure modes and damage was carried out. A two-dimensional perfectly bonded FEM analysis was conducted on 5 lightly reinforced mullion walls and the results were verified using experimental data. Reinforcement steel was considered discrete. Critical points such as yielding of the reinforcement, first crack, maximum capacity and ultimate point were evaluated in terms of shear force and drift with acceptable results. An additional model for each wall was created to evaluate the effect of bond between the steel reinforcement and the concrete. The bond strength was calculated using AIJ equations and 1mm of slip, which produced negligible differences compared with the perfectly bonded model. Crack development and distribution were compared between numerical models and tested specimens, obtaining similar patterns in all specimens. Failure modes were consistent with the experimental results. Representative shear cracks obtained in the experiment were chosen and analyzed according to the distribution of tensile strain in the numerical models. The width of these cracks was calculated and compared with up to 1% of drift angle, assuming the crack spacing equal to the spacing of the shear reinforcement. In most of cases accuracy of more than 50% was obtained.