Structure Effects on Mechanical Properties of a Novel Engineered Wood Product: Cross-Laminated-Thick Veneers Based on Infinite Splicing Technology

With increasing global concern over carbon emissions in the construction industry, cross-laminated-thick veneer (CLTV) has emerged as an innovative green building material with significant potential to promote the achievement of "dual-carbon" goals. This study developed a groove and tenon splicing technique for thick veneers, enabling infinite splicing of the length direction and the preparation of a large-size CLTV measuring 12 m (length) x 3.25 m (width) x 105 mm (thickness). The mechanical properties of CLTV were studied in relation to splice position, assembly pattern of grain directions, and layer combinations. The results showed that increasing the number of // layers (// or perpendicular to indicates grain direction of layer parallel or perpendicular to the length direction of CLTV) and using high-level layers significantly improved the compressive strength and reduced the coefficient of variation of CLTV. In terms of bending properties, reasonable splice distribution, placing // layers away from the neutral axis, and elevating layer level dramatically enhanced CLTV performance. Furthermore, the study revealed the synergistic effect among these design elements. The effects of layer level and the number of // layers on mechanical properties varied depending on splice arrangement and assembly pattern of grain directions, highlighting the importance of efficient structural design and raw material selection. This study addresses the limitations of traditional cross-laminated timber in raw material selection and production efficiency. Through structural innovation, it offers a solution for physical design and performance regulation, enabling the application of larger CLTV in wood structures and presenting new ideas for using fast-growing wood to reduce construction emissions.