Experimental testing and comparison with analytical methods for glued-in rods in cross-laminated timber
Narges Heidarzadeh, Biniam Tekle Teweldebrhan, Joshua Woods, Solomon Tesfamariam
Abstract
With the advent of engineered wood products, timber has evolved into a sustainable material for modern innovative structural systems. This resurgence in the application of timber has also spurred the development of innovative connection systems. Among various timber connection methods, glued-in rods (GiRs) have emerged as a modern solution, offering superior load-carrying capacity, aesthetic integration, and suitability for concealed applications. In this study, sixteen GiR connections in cross-laminated timber (CLT) are experimentally tested to evaluate failure modes, load–displacement behavior, and strain distribution along the rod embedment length. These experimental results, combined with data from previously published studies, are used to assess the predictive accuracy and reliability of existing analytical and empirical design equations developed for the GiR connection design. The study highlights the importance of considering both the embedment length and the grain orientation when designing GiR connections in CLT. While most existing design formulations provide reasonable strength estimates, their accuracy decreases at higher embedment lengths. Moreover, variability in failure behavior across studies underscores the complexity of GiR connections. In summary, the findings of this study provide insight into the performance of current design models and contribute to the advancement of reliable methodologies for GiR connections in CLT structures.