Failure modes and reinforcement techniques for timber beams – State of the art

•Review of typical materials, cross sections and forms of timber beams.•Description of general failure modes and their possible causes.•State of the art of established retrofitting and reinforcement techniques.•Discussion of case studies for reinforcement techniques.

Highly loaded and large span timber beams are often used for halls, public buildings or bridges. Reinforcement of beams may be required to extend the life of the structure, due to deterioration or damage to the material/product or change of use. The paper summarises methods to repair or enhance the structural performance of timber beams. The main materials/products cross sections and geometries used for timber beam are presented. Furthermore, their general failure modes are described and typical retrofitting and reinforcement techniques are given. The techniques include wood to wood replacements, use of mechanical fasteners and additional strengthening materials/products.