Physical and mechanical properties of polyurethane-bonded cross-laminated timber made with Pinus roxburghii wood

Cross-Laminated Timber (CLT) is an advanced engineered wood product mostly used for structural applications. Being lightweight, strong, eco-friendly and aesthetically sturdy, this material has gained immense popularity in the construction sector throughout the globe. Since the concept of CLT was originated in Europe, most of the work has been carried out on European softwoods. There is very little information available on the utilization of Indian softwood species for manufacturing CLT. The present study was carried out to investigate the mechanical (flexural modulus, flexural strength, compressive strength and block shear strength) and physical properties (delamination, density, water absorption, thickness and volumetric swelling) of polyurethane-bonded CLT fabricated using Pinus roxburghii (chirpine) wood, an indigenous timber species. The flexural modulus was 4.2 GPa. The average flexural, compressive and block shear strengths were 36.2, 15 and 3.5 MPa, respectively. The density of CLT samples was 0.43 g/cm³. Total delamination and maximum delamination were 6.72% and 25.38%, respectively. The thickness swelling, water absorption and volumetric swelling of CLT samples were 6.60 %, 26.96 % and 8.81 %, respectively. The findings of the present study provide valuable insights into the potential of manufacturing CLT using Pinus roxburghii wood as a construction material for low-load-bearing structures. Further studies can be carried out to assess the durability and fire performance of the CLT panels.