Behaviour of bonded-in dowel shear connections in timber lightweight concrete composite beams including effect of an interlayer

With the need of renovation in the current timber structures, use of a cement based layer is a popular solution, which improves the structural integrity and increases the structural mass. In this paper, the use of a lightweight concrete with dowel type connections is investigated since such a combination can serve for both new and existing structures. Two types of dowel connections are experimentally tested, screws and bonded-in rods, to observe their limits and the contribution of an adhesive. To extend the application to an existing structure where a wood-based flooring may be present (such as OSB), which acts as an interlayer in the composite solution, the connections are tested with an interlayer as well. To overcome this challenge, in this paper, the predrilled hole at the wood based material (timber and interlayer) is filled with an adhesive to form a bond to the connection. The experimental results indicate that the addition of an adhesive lead to a positive contribution in mechanical properties. The experimental results are compared with the analytical approaches given in the current codes. The difference in comparisons are justified and further supported with the literature.