Flexural Capacity of Glass FRP Strengthened Concrete Masonry Walls

TLDR

FRP offers a cost‑effective exterior strengthening option for unreinforced or underreinforced masonry walls, simplifying installation and reducing downtime. Six unreinforced concrete masonry walls (four 1.8 m tall and two 4.7 m tall) were tested in out‑of‑plane flexure to capacity after being strengthened with a glass FRP composite of unidirectional E‑glass fabric bonded with epoxy, fibers oriented perpendicular to the bed joints. Design equations for flexural strength were presented and, when compared to test results, overpredicted the actual capacity by no more than 20 %.

Abstract

Fiber-reinforced polymers (FRP) can provide a strengthening alternative for unreinforced and underreinforced masonry. The ease with which FRP can be installed on the exterior of a masonry wall makes this form of strengthening attractive to the owner, considering both reduced installation cost and down time of the occupied structure. Six unreinforced concrete masonry walls (four at 1.8 m tall and two at 4.7 m tall) were tested in out-of-plane flexure up to capacity. The walls were strengthened with glass FRP composite composed of unidirectional E-glass fabric with an epoxy matrix. The composite was adhered to the surface of the masonry using the same epoxy with the fibers oriented perpendicular to the bed joints. General flexural strength design equations are presented and compared with the results of the testing. It was found that the equations overpredicted the actual capacity of the test specimens by no more than 20%.