Research On Mechanical Performance Of Masonry Wall Strengthened With GFRP

Masonry is one of the oldest construction materials and is widely used in many buildings nowadays. On the other hand, many unreinforced masonry structures still exist for historical reasons, and the problems of low tensile strength and bearing capacity of unreinforced masonry make it more and more urgent to strengthen these structures. New materials of FRP (fiber reinforced polymers), which becomes popular in civil engineering recently, provides a new approach to the strengthening of masonry structures due to their high strength-to-weight ratio and ease of application, and will be of great promise in the future. This paper aims at some issues of mechanical performance for masonry wall strengthened with GFRP, namely out-of-plane flexure, finite element model under in-plane loading, and bond behavior between GFRP and brick masonry. The following studies have been carried out:1. Experiments of out-of-plane four-point bending have been carried out on specimens strengthened with bonding GFRP on the surface. The specimens are designed into two different groups, one group of which subject to bending around axis parallel to bed joint orientation, and the other subject to bending around axis normal to bed joint orientation. The failure process has been observed and three typical failure modes have been summarized. The effects of GFRP on flexural capacity and deformormation of specimen have been studied; and test results of strengthened specimens are compared with the unstrengthened ones.2. Based on the experimental results, the formulas of flexural capacity have been achieved by adopting reasonable assumptions and by employing compressive constitutive law suited for masonry materials of our country.3. Based on the double-face shear bond test results, the distributions of shear bond stress and local bond stress-slip relationship at the bond interface between GFRP and masonry have been studied, and a local bond stress-slip relationship model has been proposed. Based on the four-point bending test results of brick masonry specimens strengthened with GFRP, the strain distributions in GFRP and the shear bond stress distributions at the bond interface under different loads have been studied.4. Based on the micro-model of unreinforced masonry, the finite element model of masonry wall strengthened with FRP under in-plane loading has been proposed, in which four-node plane element is employed to model bricks, linkage element is employed to model...