Use of bolted steel plates for strengthening of reinforced concrete beams and columns

Reinforced concrete (RC) structures often need strengthening due to defective construction, having higher loads than those foreseen in the initial design of the structure, or as a result of material deterioration or accidental damage. The need for strengthening concrete structures has become a crucial problem not only in developed countries but also in China and other developing countries. The use of bolted steel plates to retrofit existing RC structural components has been proven experimentally and practically to be effective in solving the problem. In this article, experimental and numerical studies conducted at The University of Hong Kong on the strengthening of RC-coupling beams, floor beams, and columns using bolted external steel plates are summarised. Features and design principles of this strengthening method are discussed.