Glue Joints Used for Reinforcing the Damaged Ends of Wooden Beams

The development of various methods of repair and reinforcement of structural components with the use of bonding techniques has been observed over the last 30 years and has become more widely used in the rehabilitation of historical buildings. The glue joints ensure the uniform performance of structures and enable the introduction of reinforcing elements within the cross-section area of the reinforced components. Despite wide application, theoretical studies of the distribution of forces in glue joints are rarely found in literature. Discussion in this paper has been limited to the case of replacement of wooden beam ends while employing the glue joints and various types of reinforcing elements. The results of laboratory tests concerning the load capacity of the beams after reinforcement, stress patterns in the joints and the pictures of failure of elements are presented. The test results obtained were verified by application of a developed mathematical model describing the performance of "bar-wood" joints. Also the empirical expressions to determine the anchorage length of reinforcement bars in wood are presented.