The effect of alternating freezing and high temperatures on the tensile-shear strength of glued Norway spruce (Picea abies (L.) H. Karst.) and European larch (Larix decidua Mill.) wood

摘要

Wood bond strength and its durability under unstable climatic conditions is a critical factor for engineered wood products. This article aims to identify the effect of alternating freezing and high temperatures on the tensile-shear strength of adhesive-bonded wood. Emulsion polymer isocyanate and one-component polyurethane adhesives were used to bond European larch (Larix decidua Mill) and Norway spruce (Picea abies (L.) H. Karst.). The thermal loading of glued samples was carried out at temperatures of - 15 ℃/70 ℃ and - 25 ℃/70 ℃. The tensile-shear strength was determined on the glued samples with a universal testing machine. The results showed that the tensile-shear strength of the glued wood exposed to - 15 ℃/70 ℃ and - 25 ℃/70 ℃ remained unchanged compared to that of reference samples. A negligible correlation was found between the thermal loading and the shear strength of glued samples.