Materials and Structures

, 43:141 | Cite as

Experimental assessment of CFRP reinforced wooden beams by 4-point bending tests and photoelastic coating technique

  • Ludomir J. Jankowski
  • Jerzy Jasieńko
  • Tomasz Piotr Nowak
Original Article

Abstract

The article presents selected results of experimental investigations into carbon fibre reinforced plastic (CFRP) strips for strengthening wooden beams. About 100 years old beams were tested under four-point bending load. Electrical-resistance strain gauges (ERSG) together with the photoelastic coating technique (PCT) were used to determine strain distributions (also in the inserted strips). A comparison of the strain values measured by, respectively, ERSG and PCT showed significant differences (amounting to 2.2–72.5%) due to the different character of the two kinds of measurement, connected with the significant effect of wood structure on local strain distributions. Generally, the strain measurement results suggest that the proposed methods of reinforcing wooden beams with CFRP strips are useful for restoration purposes. The effectiveness of the reinforcement significantly depends on the quality of the wood-CFRP strip bond, which means the preparation of the surfaces for bonding plays an important role.

Keywords

Wooden beams Strengthening CFRP Strain measurement Photoelastic coating technique Four-point bending 

References

  1. 1.
    Jasieńko J (2003) Glue and engineering joints in repair, conservation and reinforcement of historical timber structures. Lower Silesia Educational Publishers (DWE), Wrocław [in Polish]Google Scholar
  2. 2.
    Nowak T (2007) Analysis of the static work of bent wooden beams reinforced with CFRP. PhD thesis, Wrocław University of Technology [in Polish]. http://www.dbc.wroc.pl/publication/1778
  3. 3.
    Martin Z, Stith J, Tingley D (2000) Commercialization of FRP reinforced glulam beam technology. In: Procceedings of world conference on timber Engineering, pos. P51, Whistler Resort, British Columbia, Canada, 31 July-3 August 2000Google Scholar
  4. 4.
    Borri A, Corradi M, Grazini A (2005) A method for flexural reinforcement of old wooden beams with CFRP materials. Compos Part B: Eng 36(2):143–153CrossRefGoogle Scholar
  5. 5.
    Issa CA, Kmeid Z (2005) Advanced wood engineering: glulam beams. Constr Build Mater 19(2):99–106CrossRefGoogle Scholar
  6. 6.
    Brunner M, Schnueriger M (2004) Timber beams strengthened with prestressed fibres: delamination. In: Proceedings of the 8th world conference on timber engineering, vol I. Lahti, Finland, 14–17 June 2004, pp 345–350Google Scholar
  7. 7.
    Kapkowski J, Słowikowska I, Stupnicki J (eds) (1987) Testing of stresses by the photoelastic coating method. PWN, Warsaw [in Polish]Google Scholar
  8. 8.
    Dally JW, Riley WF (2001) Experimental stress analysis. McGraw-Hill, Inc, New YorkGoogle Scholar
  9. 9.
    Jasieńko J, Nowak T (2007) Strengthening of bent timber beams in historical objects. In: Proceedings of the 16th IIWC international conference and symposium: from material to structure. Mechanical behaviour and failures of the timber structures, Florence-Venice-Vicenza, 11–16 November 2007Google Scholar
  10. 10.
    Bodig J, Jayne BA (1982) Mechanics of wood and wood composites. Van Nostrand Reinhold, New YorkGoogle Scholar
  11. 11.
    Andrae HP, Maier M, Peters H, Gusia PJ (2005) A new approach of bonded anchorages for cfrp prestressing tendons and cables. In: Proceedings of international symposium on bond behaviour of FRP in structures, Hong Kong, China, 2005, pp 45–54Google Scholar

Copyright information

© RILEM 2009

Authors and Affiliations

  • Ludomir J. Jankowski
    • 1
  • Jerzy Jasieńko
    • 2
    • 3
  • Tomasz Piotr Nowak
    • 2
  1. 1.Institute of Machine Design and OperationWroclaw University of TechnologyWroclawPoland
  2. 2.Institute of Civil EngineeringWroclaw University of TechnologyWroclawPoland
  3. 3.Politechnika WroclawskaInstytut BudownictwaWroclawPoland

Personalised recommendations