Experimental response of double-wythe masonry panels strengthened with glass fiber reinforced polymers subjected to diagonal compression tests

Many existing unreinforced masonry buildings are seismically vulnerable and require retrofitting. The present experimental study, performed on half scale double-wythe brick masonry panels strengthened by glass fiber reinforced polymers (GFRPs), aimed to investigate the efficiency of a shear reinforcement technique using externally bonded FRP composites. The test specimens were built in a manner to simulate the traditional masonry walls built in Iran. A series of two unreinforced brick panels and five GFRP strengthened panels were subjected to diagonal tension tests. The two unreinforced diagonal tension specimens presented a brittle failure due to splitting along the compressed diagonal. The key parameter was the strengthening configuration. Experimental results pointed out that GFRP reinforcement provided a less brittle failure and a noticeable load bearing capacity increase. Performances of the different reinforcement configurations were compared in terms of strength, deformation capacity, ductility, energy absorption, stiffness and mechanism of failure. Also, near the end of the paper, experimental results of three perforated masonry shear walls are reported. The walls were tested under constant gravity load and incrementally increasing in-plane loading cycles. Two of these walls and two of the diagonal tension specimens had the same geometrical reinforcement ratio in the diagonal direction.

► The typical brittle failure of URM panels is noticeably corrected by GFRP.
► GFRP is able to keep masonry together and maintain masonry panels’ integrity.
► Improvement in performance parameters of URM panels due to GFRP is substantial.