Experimental investigation on the performance of unreinforced masonry wall, retrofitted using engineered cementitious composites

Abstract

In this paper, the effect of Engineered Cementitious Composites (ECC) on the in-plane performance of a bearing unreinforced Masonry (URM) wall, is experimentally investigated. Three half scale solid walls were constructed and were tested under quasi-static lateral loading. The first specimen was an un-retrofitted masonry wall (reference wall) while the second one was retrofitted by ECC mortar connected to the wall foundation via steel rebar dowels. The third specimen was intentionally cracked during by quasi-static lateral loading to a drift of 0.35% and it then retrofitted by ECC mortar similar to the second specimen. The results indicated an increase in the retrofitted walls energy dissipation capacity and lateral strength. The shear strength and energy dissipation capacity of the retrofitted undamaged wall increased about 175% and 40%, respectively. Despite the damage to the third specimen, the shear strength and energy dissipation capacity of the retrofitted damaged wall increased about 330% and 115%, respectively. In addition, the elastic stiffness of both retrofitted specimens was about 20% higher than that of the reference specimen. The failure mode of undamaged and damaged specimens after the retrofitting, changed from bed joint sliding mode to rocking (flexural behavior) failure mode. Finally, a simple method for estimating the lateral strengths of retrofitted masonry walls is presented. The results of this method is in good agreement with the test results.