Experimental study on in-plane cyclic response of partially grouted reinforced concrete masonry shear walls

Abstract

This article describes the experimental results of ten partially grouted reinforced concrete masonry shear walls (PG-RCMSW) that were subjected to reverse lateral in-plane cyclic loads. The variables analysed in this study were: aspect ratio, shear reinforcement ratio and level of axial pre-compression. The influence of each of these variables on different structural parameters such as degradation of stiffness, shear strength, displacement ductility, dissipation of energy, hysteretic damping and level of drift, was evaluated. In addition, the precision of certain analytical expressions reported in the literature to predict the maximum shear strength of walls was examined and contrasted with the experimental results obtained.The results showed that the evolution of the damage was propagated in a similar way in all the walls tested until reaching the level of maximum strength. From this point, the evolution and extension of the damage depended on the characteristics and loading conditions particular to each wall. Also, a strong interdependence of the variables studied was identified, which became evident in the evaluation of shear strength, dissipation of energy, hysteretic damping, and level of drift. Using a bilinear idealization, displacement ductility values between 2.85 and 7.94 were found to reflect the presence of a moderate level of ductility in the walls tested. The equivalent viscous damping ratio associated with a non-linear response was found to range from 5% to 11%, indicating a moderate level of energy dissipation before the peak load was reached. Finally, the comparison between the predictions of the analytical expressions from the literature and the experimental results showed that those expressions that incorporated some interdependence in their design variables did not possess an appropriate degree of confidence to be applied in assessing the shear strength of PG-RCMSW, while expressions proposed by some international codes seem to be more reliable and conservative.