Comparison of newly proposed test methods to evaluate the bonding quality of Cross-Laminated Timber (CLT) panels by means of experimental data and finite element (FE) analysis

The effectiveness of new shear test methods for evaluating the face-bonding quality of Cross-Laminated Timber (CLT) panels was examined by comparing experimental data and numerical modelling. The common characteristic of the specimens was the loading with angle of 45° with respect to the wood grain, in order to avoid rolling shear during test. In addition, the sampling methodology along the panel was investigated, as well as the relation between shear and delamination tests, and the possibility of coupling them using the same specimen. The results demonstrated that all the proposed shear test methods were effective for evaluating the quality of bonding among layers in CLT panels; however, the practical applicability of the methods led to elect the most suitable for inclusion in technical standards. Shear and delamination results proved not to be correlated, and the results showed that the size of the specimen is a crucial factor in determining the outcomes of delamination tests. Therefore, while it is feasible to propose the coupling of accelerated aging procedures with shear tests, the size of the samples need to be higher than the one tested here.