Applications of FRP in reinforcing and strengthening concrete masonry beams.

摘要

An experimental and analytical study is conducted in order to investigate the flexural behaviour of masonry beams when reinforced or strengthened with Fibre- Reinforced Polymers (FRP) composite materials. Nine reinforced masonry beams with 4.0 m and 2.4 m clear spans were constructed to be tested under four point bending setup. The beams were subjected to increasing monotonic load up to failure, and then unloaded. Two beams have two courses of hollow concrete masonry units, and the remaining seven beams have three courses. Three masonry beams were reinforced using conventional steel rebars two of which were considered as the control specimens, while the remaining beam strengthened using two layers of Carbon Fibre-Reinforced Polymers (CFRP) sheets that were externally bonded to both sides of the beam. The remaining six beams were internally reinforced using Glass Fibre Reinforced Polymers (GFRP) rods with different reinforcement ratios. Beams were detailed to have sufficient shear reinforcement such that they do not fail in shear. Comparisons were conducted between the GFRP-reinforced and steel-reinforced control beams as well as CFRP-strengthened and steel-reinforced control beam of the flexural capacity, deformation and strains of the tested specimens. Using the acquired data from the experimental and analytical studies, effectiveness of GFRP rods as internal reinforcement for concrete masonry beams as well as the effectiveness CFRP sheets for strengthening steel-reinforced concrete masonry beams are demonstrated.