An analytical design evaluation and an experimental investigation of the flexural performance and material efficiency of T-beam panel systems designed to enhance bending stiffness and reduce rolling shear deformation in conventional cross-laminated timber (CLT) were studied. Four configurations were examined: a conventional 3-layer CLT, a 5-layer CLT-T (3-layer CLT panel with stems), and 5-layer and 6-layer CLT-Gs (with integral glulam beams). Specimens fabricated from spruce-pine-fir sawn timber were analysed and tested in accordance with the ASTM D198 and ANSI/APA PRG-320 standards. In the analytical design evaluation, Allowable stress design (ASD) reference values for bending moment capacity and bending stiffness were determined for each configuration using the shear analogy formulation. Both the analytical predictions and the experimental results showed that the T-beam configurations provided substantial gains in stiffness and strength relative to conventional CLT. The CLT-G configurations exhibited the highest performance, with the integral glulam beams effectively mitigating rolling shear deformation and shifting the governing failure mode from shear-dominated behaviour to flexural tension in the longitudinal layers.Experimental trends matched analytical predictions, confirming the validity and structural significance of the T-beam concept. Overall, the findings indicate that CLT T-beam systems offer a material-efficient strategy for enhancing flexural performance in mass-timber floor applications.
Ayodele et al. (Thu,) studied this question.