Sustainable lateral strengthening of traditional adobe walls using natural reinforcements

Abstract

In an attempt to couple sustainability with seismic resistance in adobe constructions, this study endeavors to improve the in-plane lateral performance of adobe walls using natural reinforcing materials. For this purpose, 10 adobe wall panels, each 1000 mm long, 900 mm high and 200 mm thick, were constructed and tested under the combined action of a constant vertical pre-compression stress of 0.3 MPa and lateral displacement reversals of increasing amplitude. Out of these, two specimens were used as control specimens: one wall panel tested without any strengthening and one after being plastered with straw-clay mortar. The remainder were strengthened with either externally-bonded (EB) mesh or near-surface-mounted (NSM) reinforcement and finally finished with a plaster of straw-clay mortar. The experimental intent was to use locally available, sustainable reinforcing materials such as palm fibers and reeds. Nonetheless, a wall panel was also strengthened with a special type of plastic mesh for comparison purposes. The results were described in terms of lateral load–displacement hysteretic behavior, ultimate strength, displacement capacity, ductility factor, energy dissipation, and equivalent viscous damping. The experimental findings revealed that the structural responses of the adobe walls could be significantly improved using natural reinforcement materials. In addition, the externally-bonded (EB) mesh of palm fibers was found to outperform the plastic one of similar grid dimensions. Finally, while both EB meshes of dense grid dimensions and NSM diagonal reeds could significantly improve the in-plane lateral performance of adobe walls, the former was found more effective in increasing energy dissipation capacity and equivalent damping ratio.