Investigation of bending properties of cross laminated timber made of Uludağ fir and black pine

In this study, flexural strength and modulus of elasticity (MOE) of cross-laminated timber (CLT) made of the Uludag fir and black pine wood, which are domestic coniferous tree species included in the scope of the EUROCODE 5, and polyvinyl acetate (PVAc) adhesive were investigated. CLTs, prepared with three layers, were pressed under the pressure of 0.4 N/mm2, the temperature of 35°C and the time of 150 min. Three-point bending tests were applied to determine flexural strength and MOE by obtaining load-deformation curves of solid wood and CLTs made of the Uludag fir and black pine wood. The average flexural strength of the solid Uludag fir and black pine was 65 N/mm2 and 83.8 N/mm2. The average flexural strength of the CLTs made of the Uludag fir and black pine wood was 38.4 N/mm2 and 64.6 N/mm2, respectively. Those of MOEs were 9093.5 N/mm2, 11068.8 N/mm2, 5273.4 N/mm2 and 8657.0 N/mm2, respectively. It resulted that solid wood and CLT made of black pine wood had more strength than those of Uludag fir. Analysis of variance also showed that wood species have a statistically significant effect on flexural strength and MOE of the materials. Consequently, the acquisition of domestic coniferous trees, the production of the CLTs made of these woods and the determination of their mechanical properties are vital in the structural analysis and member design of these materials in the wood construction industry in Turkey.