DOI QR코드

DOI QR Code

Retrofitting of squat masonry walls by FRP grids bonded by cement-based mortar

  • Popa, Viorel ;
  • Pascu, Radu ;
  • Papurcu, Andrei ;
  • Albota, Emil
  • Received : 2014.11.10
  • Accepted : 2015.11.02
  • Published : 2016.01.25

Abstract

For seismic retrofitting of masonry walls, the use of fibre reinforced cement-based mortar for bonding the fibre grids can eliminate some of the shortcomings related to the use of resin as bonding material. The results of an experimental testing program on masonry walls retrofitted with fibre reinforced mortar and fibre grids are presented in this paper. Seven squat masonry walls were tested under unidirectional lateral displacement reversals and constant axial load. Steel anchors were used to increase the effectiveness of the bond between the fibre grids and the masonry walls. Application of fibre grids on both lateral faces of the walls effectively improved the hysteretic behaviour and specimens could be loaded until slip occurred in the horizontal joint between the masonry and the bottom concrete stub. Application of the fibre grids on a single face did not effectively improve the hysteretic behaviour. Retrofitting with fibre reinforced mortar only prevented the early damage but did not effectively increase deformation capacity. When the boundaries of the cross sections were not properly confined, midplane splitting of the masonry walls occurred. Steel anchors embedded in the walls in the corners area effectively prevented this type of failure.

Keywords

squat masonry walls;fibre reinforced mortar;fibre grids;experimental testing;seismic retrofitting;hysteretic behaviour;strength;energy dissipation capacity

References

  1. Augenti, N., Parisi, F., Prota, A. and Manfredi, G. (2011), "In-plane lateral response of a full-scale masonry subassemblage with and without an inorganic matrix-grid strengthening system", J. Compos. Constr., 15(4), 578-590. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000193
  2. ACI 374.1 (2013), Guide for testing reinforced concrete structural elements under slowly applied simulated seismic loads, ACI Standard, Reported by ACI Committee 374, Farmington Hills, Michigan, USA.
  3. Aldea, C.-M., Mobasher, B. and Jain, N. (2007), "Cement-based matrix-grid system for masonry rehabilitation", ACI Symposium "Thin Fiber and Textile Reinforced Cementitious Systems", (SP 244CD:9). American Concrete Institute.
  4. Bruneau, M. (2002), "Building damage from the Marmara, Turkey earthquake of August 17", J. Seismol., 6(3), 357-377. https://doi.org/10.1023/A:1020035425531
  5. D'Ayala, D. and Paganoni, S. (2009), "Assessment and analysis of damage in L'Aquila historic city centre after 6th April 2009", Bull. Earthq. Eng., 9(1), 81-104.
  6. ElGawady, M., Lestuzzi, P. and Badoux, M. (2004), "A review of conventional seismic retrofitting techniques for URM", 13th international brick and block masonry conference, Amsterdam, Eindhoven University of Technology.
  7. Eser, D. and Mustafa, E. (2008), "Earthquake risk and its mitigation in Istanbul", Nat. Haz., 44(2), 181-197. https://doi.org/10.1007/s11069-007-9110-9
  8. Fattal G., Simiu, E. and Culver, C. (1977), "Observations on the behaviour of buildings in the Romania earthquake of March 4, 1977", NBS Special publication 490, US Department of Commerce/ National Bureau of Standards, USA.
  9. EN 12190 (1988), Products and systems for the protection and repair of concrete structures - Test methods - Determination of compressive strength of repair mortar, European Committee for Standardization, Brussels.
  10. EN 13412 (2006), Products and systems for the protection and repair of concrete structures - Test methods - Determination of modulus of elasticity in compression, European Committee for Standardization, Brussels.
  11. EN 196-1 (2005), Methods of testing cement - Part 1: Determination of strength, European Committee for Standardization, Brussels.
  12. FEMA 461 (2007), Interim testing protocols for determining the seismic performance characteristics of structural and non-structural components, Report No. FEMA 461, Washington DC, USA.
  13. Lagomarsino, S. (2012), "Damage assessment of churches after L'Aquila earthquake (2009)", Bull. Earthq. Eng., 10(1), 73-92.
  14. Papanicolaou, C., Triantafillou, T., Karlos, K. and Papathansoiu, M. (2007), "Textile-reinforced mortar (TRM) versus FRP as strengthening material of URM walls: in-plane cyclic loading", Mater. Struct., 40(10), 1081-1097. https://doi.org/10.1617/s11527-006-9207-8
  15. Papanicolaou, C., Triantafillou, T., Papathansoiu, M. and Karlos, K. (2008), "Textile-reinforced mortar (TRM) versus FRP as strengthening material of URM walls: out-of-plane cyclic loading", Mater. Struct., 41(1), 143-157.
  16. Papanicolaou, C., Triantafillou, T. and Lekka, M. (2011), "Externally bonded grids as strengthening and seismic retrofitting materials of masonry panels", Constr. Build. Mater., 25(2), 504-514. https://doi.org/10.1016/j.conbuildmat.2010.07.018
  17. Penna, A., Morandi, P., Rota, M., Manzini, C.F., Porto, F. and Magenes, G. (2014), "Performance of masonry buildings during the Emilia 2012 earthquake", Bull. Earthq. Eng., 12(5), 2255-2273. https://doi.org/10.1007/s10518-013-9496-6
  18. Popa, V., Vacareanu, R. and Karadogan, F. (2013), "Post-earthquake investigation and seismic evaluation of a damaged RC building in Van, Turkey", Proceedings of the 10th International Conference on Urban Earthquake Engineering, Tokyo Institute of Technology, Tokyo, Japan.
  19. Saatcioglu, M., Serrato, F. and Foo, S. (2005), "Seismic Performance of Masonry Infill Walls Retrofitted With CFRP Sheets", 7th International Symposium of Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures (FRPRCS-7).SP-230-20, 341-351.
  20. Seki, M., Vacareanu, R., Saito, T., Cotofana, D., Lozinca, E., Popa, V. and Chesca, A.B. (2008), "Cyclic shear tests on plain and FRP retrofitted masonry walls", Proceeding in the 14th World Conference on Earthquake Engineering (14WCEE), International Association for Earthquake Engineering.
  21. Seki, M., Popa, V., Cotofana, D., Lozinca, E., Chesca, A.B. and Vacareanu, R. (2010), "Experimental study on confined masonry squat walls", 14th European Conference on Earthquake Engineering, Ohrid, Macedonia.
  22. Sorrentino, L., Liberatore, L., Decanini, L. and Liberatore, D. (2013), "The performance of churches in the 2012 Emilia earthquakes", Bull. Earthq. Eng., 12(5), 2299-2331.
  23. Spence, R. (2007), "Saving lives in earthquakes: successes and failures in seismic protection since 1960", Bull. Earthq. Eng., 5(2), 139-251. https://doi.org/10.1007/s10518-006-9028-8
  24. Tomazevic, M., Klemenc, I. and Weiss, P. (2009), "Seismic upgrading of old masonry buildings by seismic isolation and CFRP laminates: a shaking-table study of reduced scale models", Bull. Earthq. Eng., 7(1), 293-321. https://doi.org/10.1007/s10518-008-9086-1
  25. Triantafillou, T. (1988), "Strengthening of masonry structures using epoxy bonded FRP laminates", J. Compos. Constr., 2(2), 96-104.