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.
The increasing number of wood structure amongst large and potentially public buildings gave a new impulse to the assessment of timber structures. For assessing the state of timber elements, cracks are a key indicator. Therefore, experimental and numerical investigations on not cracked and partly cracked timber members were carried out and analysed. The results show no influence on the stiffness and modulus of elasticity for partly cracked beams. The experimental results were used for the development of analytical and validation the numerical solutions for the assessment of the residual load carrying capacity of cracked timber members. Several models predicting the residual load carrying capacity depending on the crack situation are presented.