MASONRY
STRUCTURES STRENGTHENING WITH FRP SHEET
by
Graduate Student
Department of Architectural
Engineering
Pennsylvania State
University
Fiber reinforced plastic (FRP) materials are being considered for use in the construction industry due to their lightweight, high strength, high stiffness, and excellent corrosion resistance. Recently, FRP sheets have been used in strengthening and repairing the concrete and masonry structures. Economics dictates that these materials will be applied in narrow strips, rather than full-width. This study investigates how forces are transferred from narrow reinforcing strips to brick substrates. Glass and carbon FRP (GFRP and CFRP) sheets are applied on brick specimens and then they are investigated by experiments and FEM analysis. Two different types of brick specimens such as push-apart and brick prism specimens are constructed and then tested in tension and 4-point bending, respectively. Finite element modeling is used to predict the behavior of the specimens in the region of the sheet-bonded reinforcement and at the mortar joint. Both the experimental and the analytical results show the development of high tensile strains in the masonry. Push-apart specimens with narrow sheet reinforcement fail by rupture of the CFRP sheet. On the other hand, the specimens reinforced with wider sheets show an assortment of premature failure modes such as FRP sheet breakage, debonding, and brick failure. All of the specimens reinforced with GFRP sheet are failed in the FRP sheet. Brick prism specimens reinforced with CFRP show the debonding of sheet and shear failure in brick while the specimens reinforced with GFRP sheet show the sheet rupture and mortar joint failure. The FRP sheet increases the out of plane strength of the masonry and the application of uniaxial tensile reinforcement to brittle substrate calls for considerable cautions and premature failure modes. In addition, structures and strain transfer occurs in localized area around the FRP sheet.