Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2754

Full Length Research Paper

GFRP bar element to strengthen timber connection systems

  Mehmet Saribiyik* and Tahir Akgül
Faculty of Technology, Sakarya University, 54187 Sakarya, Turkey.
Email: [email protected]

  •  Accepted: 03 June 2010
  •  Published: 04 July 2010


Timber is an excellent construction material with a strength-to-weight ratio comparable with steel and concrete. It is necessary to strengthen the timber, particularly in the weak joint places, in order to obtain both durability and originality. The aims of strengthening in the connecting places are to decrease the stress concentration, keep on the fibre continuity, and reduce disadvantages of connection element including nail and bolts. Nowadays, Glass Fibre Reinforced Plastics, (GFRP) produced via pultrusion process, are used to strengthen the structural elements because of its high strength, light weight, corrosion resistance and easy application of the structures. The aim of this study is to obtain the fibre continuity of connecting places of timber using GFRP bar elements. Mechanical performances of the connecting places of longitudinal notched lap joints have been investigated. Specimens have been prepared from black pine timber. Seven different groups of specimens, one group massive timber, one group only adhesively bonded and remaining strengthened with pultruded GFRP bar samples, have been prepared to determine the performances of the connections. The specimens have been tested subjected to bending strength and the obtained results have been compared to with each others. The outcomes demonstrate the fact that the bending strength of the connection strengthened with GFRP bar has about 300% higher than adhesively bonded connection. Timber is an excellent construction material with a strength-to-weight ratio compare to with steel and concrete. However, its use to date in the construction industry has been hampered by the weakness of the jointing systems used. In order to decrease the stress concentration and reduce disadvantages of connection element it is necessary to strengthen timbers particularly in the weak joint places.


Key words: Timber structures, bending strength, longitudinal notched lap joint, glass Fibre reinforced plastic.