1 Research Associate, Centre for Infrastructure Performance and Reliability, School of Engineering, The University of Newcastle, Callaghan NSW 2308, Australia. Chaminda.Konthesingha@newcastle.edu.au
2 Associate Professor, Centre for Infrastructure Performance and Reliability, School of Engineering, The University of Newcastle, Callaghan NSW 2308, Australia. Mark.Masia@newcastle.edu.au
3 Research Associate, Centre for Infrastructure Performance and Reliability, School of Engineering, The University of Newcastle, Callaghan NSW 2308, Australia Robert.Petersen@newcastle.edu.au
4 Emeritus Professor, Centre for Infrastructure Performance and Reliability, School of Engineering, The University of Newcastle, Callaghan NSW 2308, Australia Adrian.Page@newcastle.edu.au
ABSTRACT
An experimental study was conducted to assess the effect on strength, displacement capacity and ductility of strengthening unreinforced masonry (URM) shear panels with near surface mounted (NSM) fibre reinforced polymer (FRP) strips. A total of twenty three (23) wall panels (5 URM and 18 reinforced) were subjected to vertical pre-compression combined with increasing reversing cycles of in-plane lateral displacement under fixed-fixed boundary conditions. Two wall aspect ratios were tested: aspect ratio 1.0 (1200mm high x 1200mm long x 110mm thick) and aspect ratio 0.5 (1040mm high x 1910mm long x 110mm thick). For aspect ratio 1.0, eight panels were tested (2 URM and 2 specimens for each of three different NSM FRP reinforcement schemes). For aspect ratio 0.5, fifteen panels were tested (3 URM and 2 specimens for each of six different NSM FRP reinforcement schemes). The experimental program was designed to produce diagonal cracking in the URM specimens and hence investigate the effectiveness of the various reinforcement schemes in controlling this failure mode. This was achieved for the aspect ratio 1.0 panels for which the study revealed that the FRP strengthening was effective in improving the ultimate load resisted by the wall panels (increases of up to 9%), the displacement capacity (133%) and ductility (108%) compared to the URM response. For the aspect ratio 0.5 panels, base sliding failures dominated the experimental program, making it difficult to fully assess the effectiveness of the various reinforcing schemes.
KEYWORDS: masonry, strengthen/retrofit, cyclic, shear, nsm, frp
253.pdf
