Behavior of post-tensioned dry-stack interlocking masonry shear walls under cyclic in-plane loading

Abstract

Dry-stacked interlocking masonry (DSIM) systems were developed worldwide to minimize the disadvantages of traditional masonry systems such as shrinkage, weak joints, and the need of skilled labors. Nevertheless, dry-stacked walls are recommended to be designed as reinforced and fully grouted. In this paper an experimental study conducted to evaluate the in-plane behavior of full-scale DSIM shear walls under cyclic in-plane loading and to explore the effectiveness of using post-tensioning (PT) instead of grout and reinforcement. A sliding control system to enhance the ductility of the DSIM system was developed. The test program consists of nine masonry shear walls constructed with three different types of locally available concrete masonry blocks (Conventional, Azar and Sparlock). The specimens were tested under reversed cyclic lateral load up to failure. The test results, including load displacement response, failure mode, modes of deformation, residual drift ratio, displacement ductility, wall stiffness, stiffness degradation, and energy dissipation are presented and discussed. The results showed that a similar behavior of Azar and conventional masonry systems in both reinforced and PT specimens. The utilization of PT with excluding the grout in DSIM shear walls improved the displacement ductility, effective stiffness and energy dissipation. Finally, the developed sliding control system in DSIM PT specimens increased the sliding contribution to 35% of total deformation, hence improved the displacement ductility.