Investigation of the Change in the Load-Carrying Capacities of RC Beams Strengthened with Steel Plate Glued to Bottom of the Beam

Arslan G., Öztürk M., Arabacı R. M.

First International Symposium on Innovations in Civil Engineering and Technology (1ST I CIVILTECH) , Afyon, Turkey, 23 - 25 October 2019, pp.447-452

  • Publication Type: Conference Paper / Full Text
  • City: Afyon
  • Country: Turkey
  • Page Numbers: pp.447-452
  • Yıldız Technical University Affiliated: Yes


The existing concrete structures and/or elements may be required to strength or rebuilt due to insufficient structural performance. The choice between them is based on specific factors of each individual case, but certain issues are considered in every case. Different approaches are available for strengthening of existing concrete structures and/or elements. The most preferable approaches are bonding with steel plates, glass fiber reinforced plastic, fibre reinforced polymer sheets, external prestressing, external post tensioning and additional concreting. In recent years, the use of plate bonding technique in reinforced concrete (RC) structural members is of interest to many studies due to several advantages such as easy construction work, and minimum change in the overall size of the structure after plate bonding. In this study, the change in the strength of RC beams strengthened with a steel plate glued to the bottom of the beam by using epoxy and also bolted to the beams at their ends was investigated in experimentally. The strengthened RC beams with shear span-to-effective depth ratios of 4.5 have been tested under three-point loading to determine their load and deflection capacities using a displacement-controlled loading machine. The load-displacement curves obtained for each beam were compared with the corresponding RC beam without any strengthening (reference). It was observed that the ductility and load-carrying capacities of strengthened beams were increased compared to the reference beams. Since, steel plate glued to the bottom of the beam has low bond strength with concrete, bond failure was apparent in the experiments. However, steel plate glued to the bottom of the beam resulted in significant increases in the load-carrying and deflection capacities. The load-carrying capacity was increased by approximately 13% and the maximum deflection at the mid-span was reached approximately %17 more than that of the reference beam. Also, the strengthening bolted to the beams increased the load carrying 36% compared to the capacity of the reference beam, but the mid-span deflection under the maximum load was reached at a midspan deflection approximately %26 less than that of the reference beam.