Features of production and application of glued wooden beams in cottage construction

Abstract

This paper discusses the technological features of the production and use of laminated veneer lumber in cottage construction. The main properties of aluminosilicate glue for gluing pine lamellas have been determined. Changes in both the dynamic and plastic viscosity of aluminosilicate glue are given depending on the spindle rotation speed and shear rate. Equations describing these dependencies are given. These dependencies influence the choice of the method for applying the aluminosilicate glue to the substrate surface. It has been shown that a change in dynamic viscosity from 1662 to 1268 cP in the operating speed range from 20 to 30 RPM and shear rate from 4.2 to 6.3 1/s provides a small shear force from 69.9 to 79.88 dynes/cm2, which makes it easy to apply the glue with a brush or a special roller. It is noted that aluminosilicate glue with a density of 1.54 g/cm3 has a low surface tension of 54 mN/m, which affects the contact angle and the tendency to spread on a pine base. It has been found that an increase in the spreading coefficient results in more complete wetting. It is shown that with an increase in the curing time of the glue joints, the shear strength along the fibers and the elastic modulus on the 28th day increase by 1.63/1.1 times as compared with the seven-day age. An increase in strength and elastic modulus is associated with the passage of crystallization processes in an aluminosilicate gel with the subsequent formation of zeolite-like formations. It is noted that the increase in the value of the breaking load of the samples at the age of 28 days is 1.63 times higher than after 7 days of curing, for determining the values of the shear modulus and elasticity does not have such a decisive importance and this decrease is 5.1%.