This paper presents an investigation conducted on repairing damaged Reinforced Concrete (RC) beams with a large rectangular web opening using externally bonded plates. Carbon Fiber Reinforced Polymer (CFRP) and steel plates were used as repair materials with two types of configuration - hexagonal and rectangular - for each material. The beams contain a rectangular web opening at one of the shear spans. The externally bonded CFRP sheet and steel plate were found to be effective in repairing RC beams with a large rectangular web opening. The results showed that CFRP plates perform better than steel plates and that the rectangular configuration is better than the hexagonal one.

The effect of steel plate thickness on the repair effectiveness of RC beam is presented in this paper. A total of fine beams were tested, one beam repaired by CFRP with a thickness of 1.2 mm and used as a control beam, and three beams repaired by a steel plate. Steel plates with a thickness of 2 mm, 3 mm, and 4 mm were used in repairing the beams. The maximum load-carrying capacity, deflection at mid span and edge of the opening, strain in steel bars, strain in externally bonded plates, crack patterns, and failure modes were observed on each beam. The externally bonded CFRP sheet and steel plates were found to be effective in the repairing of RC beams with large rectangular web opening. The results show that increasing steel plate thickness has little effect on the maximum load capacity. The CFRP plate is more effective than steel plate in increasing the load capacity of beams.

The construction of modern buildings requires many pipes and ducts in order to accommodate essential services such as air conditioning, electricity, telephone, and computer network. Web openings in concrete beams enable the installation of these services. A number of studies have been conducted with regards to reinforced concrete beams which contain web openings. The present paper aims to compile this state of the art work on the behaviour, analysis and design of Reinforced Concrete (RC) beams with transverse web openings. A variety of aspects will be highlighted and discussed including the classification of openings, guidelines for opening location, and the structural behaviour of RC beams with web openings. Various design approaches will also be detailed, for example the American Concrete Institute (ACI) approach, the Architectural Institute of Japan (AIJ) approach and the strut and tie method. Moreover, the strengthening of RC beams with openings using Fibre Reinforced Polymer (FRP) material and steel plates is presented. Finally, directions for future research based on the gaps which exist in the present work are presented. (C) 2012 Elsevier Ltd. All rights reserved.

This paper presents the results of an experimental study regarding the repair effectiveness of steel plates for damaged Reinforced Concrete (RC) beams with a circular web opening at shear zones. It highlights the effect of fixing the steel plates on the damaged beams on the load capacity, deflection, steel strain, steel plate strain and failure mode. In the experimental program, three beams were used, with one solid beam used as a control beam and the other two beams repaired by using two configurations (incline and vertical) of steel plate. The results revealed the efficiency of using steel plates for the repairing of damaged beams with a circular opening, in that it increases the ultimate capacity of the beams significantly and reduces the deflection under the opening. Furthermore, it was found that using an incline configuration of steel plate for repairing of beams with a web opening is much more efficient than the use of the vertical configuration. Using an inclined configuration not only increased the ultimate capacity of the beams, it also changed the mode of failure from shear mode to flexural mode.