Manufacturing high strength glue-laminated timber beams from Poplar-an important multipurpose tree species

Fast-growing tree species such as poplar, eucalyptus and paulownia are important source of supplying wood due to short production time and low cost which have been cultivated in many parts of Iran. These species produce about ۵-۴۰ m۳/year wood per hectare that are used in wood industries. It is necessary to manufacture value added products such as furniture, engineered wood products which applied in residential construction for efficient use of wood from fast growing trees such as poplar. In this study poplar wood was used for producing of glued-laminated timber. Bending strength of glulam was experimentally measured by Instron according to ASTM D ۷۳۴۱.. The results revealed that modulus of rupture and modulus of elasticity of glulam were ۴۸.۱ and ۴۳۳۰ MPa, respectively. The low density and strength wood of poplar result in low bending performance of glulam beams. Therefore, glulam beams were reinforced by galvanized steel, aluminum sheet and glass fiber reinforcement polymer. The modulus of rupture of reinforced beam by GFRP, aluminum and galvanized steel sheet were increased to ۶۸.۵۷, ۷۵.۸۹ and ۸۲.۹۶ MPa, respectively. Their corresponding modulus of elasticity values were ۵۵۶۰, ۶۸۲۲ and ۱۰۱۶۶ MPa, respectively. The results indicated that bending strength of the glulam beams significantly improved by reinforcement and make it possible to produce high strength beam from low-density polar wood.

Keywords:

Glued laminated timber , GFRP wrap , aluminum sheet , reinforcement , flexural performance.