Improving the seismic behaviour of RC frames with mortarless blocks

This paper investigated the effects of mortarless blocks on a reinforced concrete (RC) frame based on computational and experimental analyses by comparing its behaviour with those of traditional frames with and without walls. The effects of the joint between the wall and frame were investigated using flexible and stiff joints. The use of a flexible joint prevented segregation between the wall and frame. The frame with traditional infill had increased lateral rigidity (1.44 times of the bare frame). A dry stack wall with mortar between the wall and frame increased the lateral rigidity by 1.25 times. The frame with the polymer exhibited a behaviour similar to that of the bare frame, especially with respect to the initial stiffness. In the computational analysis, in which the lateral drift of the RC frames was as high as 0.08, it was concluded that the mortarless masonry allowed a 17 % increase in load capacity compared with that of the bare frame. The dry stack masonry increased the lateral stiffness of the bare frame by only 10 %, whereas the traditional infill wall increased the stiffness of the bare frame by 1.42 times in computational analysis. When a polymer was used between the dry stack wall and frame, the stiffness was similar to that of the bare frame. Thus, dry-stack masonry walls with different gap fillers can be used to increase the period of structures as an alternative approach to earthquake-resistant structural design. The use of a polymer decreased the wall damage by reducing the stresses and allowed the highest lateral drift. Compared with the RC frame without walls, the dry-stacked masonry-infilled frame with the polymer binder was slightly more ductile.