Strengthening of reinforced concrete flexural members using externally applied steel plates and fibre composite sheets — a survey

In Canada, as in many other parts of the world, the deterioration of reinforced and prestressed concrete bridges and parking garage structures has reached alarming proportions. Many of these structures face very expensive rehabilitation work or outright replacement. Although strengthening reinforced concrete structures using externally bonded or bolted steel plates is a technology that is not widely known in North America, a number of structures in Europe, Australia, and South America have been rehabilitated using this method. The weight of the steel plates, which makes them difficult to handle in the field, and their susceptibility to corrosion have led to research into the possibility of replacing steel plates with high strength fibre composite sheets. Fibre reinforced composite sheets are composed of carbon, glass, or aramid fibres, bound by a resin epoxy. In addition to being light in weight, these materials do not corrode. Very recently, a few bridges have been repaired in Europe using carbon fibre and glass fibre reinforced plastic sheets. This paper reviews the case studies and research pertaining to the use of steel plates and fibre composite sheets to strengthen and repair reinforced concrete flexural members. Key words: rehabilitation, strengthening, advanced composite materials, fibre reinforced composites, bonding.