Experimental performance of FRCM retrofit on out-of-plane behaviour of clay brick walls

In this paper the capacity of an innovative composite basalt grid with inorganic matrix (FRCM) has been evaluated both in terms of repairing pre-damaged and strengthening clay brick walls under out-of-plane loads. Experimental tests have been performed on full scale clay brick walls subjected to out-of-plane loads. A wall, damaged after a test, has been repaired by means of basalt FRCM. A similar wall has been tested directly, without pre-damage, after strengthening by means of FRCM. This allowed to remark the effect of retrofitting pre-damaged and new walls. To simulate a non-uniform out-of-plane behaviour of the wall, two adjacent edges of the wall have been constrained and the other two were left free while a pointwise normal force has been applied at the free opposite corner of the wall. The purpose of this work was to assess the potentiality of FRCM to recover the capacity of a wall after significant damage and to increase the global response of strengthened wall not previously damaged. The experimental results demonstrated that the externally bonded strengthening was able to prevent a brittle failure and it was not affected by debonding; ultimate load of the retrofitted wall almost doubled with respect to the unreinforced configuration, despite complex stress state, and that the failure was governed by shear sliding at higher displacement levels.