Experimental Investigation of Hollow Brick Unreinforced Masonry Building Retrofitted by Ferrocement Layers

Abstract

A retrofitting method for hollow brick Unreinforced Masonry (URM) buildings has been developed using ferrocement layers with the bandage system. An experimental study on hollow brick URM houses with and without ferrocement layers was conducted. Two specimens of a quarter-scale hollow brick house model consisting of four walls with the size 104cm x 110cm were constructed. The first model (B1) is the original hollow brick URM house without mortar plaster, and the second model (B2) is the same masonry house retrofitted by providing bandage ferrocement layers on both sides of the walls, which act as sandwich structures. Both specimens were tested by using a shaking table (304x190) cm 2 with input motions from 0.3g to 0.6g. The test results show that the damage to the original URM house model was initially found near the door opening at input motion 0.3g and the applied additional uniform load of 200 kg on the top of the specimen. Then, the cracks were developed and spread to the east side of the wall with the increase of the uniform load, and finally, the house model collapsed at input motion 0.6g and 500 kg additional uniform load. Meanwhile, the hollow brick URM house strengthened by using bandage ferrocement layers shows excellent performance without any damage up to input motion 0.6g. These results indicated that the ferrocement layer significantly enhanced in ductility of the hollow brick URM house model, and it was effective in preventing the collapse of the hollow brick masonry walls when earthquakes happen.