CLT_joint - Efficient, systematized and quality-tested connection solutions for cross laminated timber

Cross laminated timber (CLT) and self-tapping screws are considered to be the most important developments in timber construction of the last 30 years. Both together open up completely new possibilities for timber construction and lead it into areas which have been dominated by mineral-based building materials up to now. With a focus on solid wood construction with CLT, systematic and versatile connection solutions tailored to this product have been largely lacking to date, despite the given dynamic developments taking place worldwide. At present, for the connection / joining of CLT components connection solutions are borrowed from lightweight wood construction. However, these are not able to guarantee the high performance of the CLT product in the connection area nor the often-required amount of energy dissipation. An additional complication in the development of adequate connection solutions adapted to the CLT building product is that there is generally a high diversity in terms of joint type, construction method and requirement profile. The aim of the research project is a systematic and fundamental investigation of the connection situations of CLT construction elements and related requirements, with a focus on load effects on the material and product behaviour in case of locally concentrated, quasi-static and cyclical loading as well as the recording and consideration of tolerances. This is to create a sound basis for the development of systematic and versatile connection solutions for solid wood construction with CLT, combined with the development of an automated, quality-proof application unit as an integral part of the joining process of CLT elements, for which corresponding control parameters and quality assurance measures are being researched. In the development of connection solutions themselves, flexibility as well as the achievement of defined failure mechanisms depending on the type of connection joint, type of stress and direction of stress on the basis of a fundamental discussion of the structural behaviour to be aimed at and the separation into a timber connection and an assembly joint are also in the foreground.