In recent years, wood has again become an attractive building material, due to increased ecological awareness and the general trend of environmentally friendly construction. One alternative use of beechwood, which is in abundance in Slovenia, is the production of glulam beams. Due to some of the deficiencies of beechwood, the aim of the master’s thesis was to develop a combined beech and spruce glulam beam (hybrid beam), which should contain such a proportion of beechwood so that its utilisation would be optimised in terms of stiffness, strength and lightweight. To find out if the widely used MUF and PUR adhesives are suitable for the production of such beams, shear and delamination tests were performed according to the SIST EN 14080:2013 standard . The requirements were met in all cases. Two beech, spruce and hybrid glulam beams, with outer lamellas from beech and inner lamellas from spruce wood, were made. The dynamic modulus of elasticity was determined for all the used lamellas, as well as the glulam beams. The influence of the proportion of beechwood on the stiffness of a glulam beam was calculated using composite beam theory. However, the impact on the strength was studied by the simulations carried out in the ABAQUS software. Based on the four-point bending test, models of spruce and beech beams were made. For hybrid beams, 12 models with different thicknesses of beech lamellas were created. With regard to the stiffness and lightweight, it was found that the optimum proportion of beechwood in the hybrid beam is zero, since the highest specific moduli of elasticity, were obtained with the spruce beams. The results obtained in the simulations did not show a good agreement with the experimental ones; therefore, the optimum proportion of beechwood in a beam in terms of strength and lightweight was not determined. A good correlation between the static and dynamic moduli of elasticity of the beams was found.
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