We were studying the influence of application rate of adhesive and the ratio between the adhesive and hardener on the shear strength of adhesive bond. We tested the following application rates: 250 g/m2, 300 g/m2, 350 g/m2, and 400 g/m2; the ratios between the adhesive and the hardener were: 100:20, 100:35, 100:60 and 100:100. For testing, we used spruce wood (Picea Abies K). We prepared lamellas with dimensions 600 mm x 120 mm x 32 mm, which we bonded with a melamine-urea-formaldehyde glue, which is used for bonding laminated beams. We glued three lamellas together to obtain two adhesive joints, which were tested. The samples were made as according to standard EN 14080, 2013. The tests were performed on Zwick testing machines. All the test pieces were visually evaluated and it was determined that there was a 100 % fracture of wood, which means that the adhesive is sufficiently penetrated in the timber and ensures a good adhesion between the adhesive and the wood. We determined that all the specimens had shear strength of more than 6 N/mm2, which is the lower limit of the standard SIST 14080, 2013.
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