SHEAR RESPONSE OF BRICK MASONRY WALLS EXTERNALLY RETROFFITED WITH BONDED CARBON FIBER FABRIC

Abstract

Earthquakes have produced extensive damage in masonry structures due to in-plane shear actions. Various techniques of retrofitting have been studied, among them, the retrofitting of masonry walls with externally bonded fiber reinforced polymers (FRP), which has been shown to be an effective reinforcing technique, producing important increases in the maximum strength and in the deformation capacity of the walls.
The shear response of un-reinforced hollow clay brick masonry walls (URM), with two configurations of carbon fiber fabric (CFRP) externally bonded on both sides, were studied. A total of twelve full-scale walls were subject to cyclic, in-plane shear loading. Two non-retrofitted walls, five diagonally reinforced walls and five horizontally retrofitted walls were tested.
The experimental results show that in the retrofitted walls the load that produced the first major crack was larger than in the non-retrofitted walls. Also, the retrofitted walls had an important increase of maximum strength and deformation capacity. The cracking pattern changed from a single wide crack to several thinner cracks, and the failure mode was less brittle than in the case of URM walls. Finally a simple model to estimate de cracking load and maximum strength are proposed.