Out-of-Plane Strengthening of Reinforced Masonry Walls using Near-surface Mounted (NSM) FRP Bars with Epoxy and Cementitious Material

The study reported here investigates the out-of-plane flexure behaviour of reinforced masonry walls strengthened with (NSM) fibre reinforced polymer (FRP) bars and subjected to cyclic loading. An extensive experimental work was carried out to study the effect of different technique of strengthening using FRP as a NSM or external bonded on out of plan behaviour of reinforced masonry walls. This paper presents part of this extensive study that deals with FRP strengthening using epoxy and cementitious based as an embedding material. Fourteen medium scale reinforced masonry walls were built for this study. These reinforced walls were strengthened using CFRP (bars and tapes) and GFRP (bars) as a near surface mounted technique (NSM); constant mild steel reinforcement ratio (ρ) was used. These simply supported walls were tested under an out-of-plane cyclic load applied along two line loads. This investigation examines the effect of different parameters, these parameters related to FRP (type and amount), bond pattern (stack and running), and existing of FRP bars in compression face of the wall. The test results indicated the behaviour of the masonry walls was significantly dependent on the type of FRP used. A significant increase in the strength of out-of-plane reinforced wall strengthened with FRP compared to the unstrengthened reinforced wall. Different modes of failure occurred in the strengthened reinforced walls, including a punching shear failure through the concrete block, as well as a debonding of FRP reinforcement from the masonry substrate