| 摘要 |
The beam is made from timber strips (3, 5), wider than they are thick, preferably less than 5 mm thick and at least five times as wide, glued together with adhesive layers preferably under 1 mm thick. The strips are in two groups lying in different planes, e.g. perpendicular to one another, and the beam can have a rectangular, T-shaped or trapezoid cross-section. The beam can be reinforced with inserts of metal, synthetic, mineral or vegetable fibres, preferably of steel, glass, carbon or polymer, set partially in grooves in the strips, to help withstand various stresses. The strips can be made from different woods, preferably with oak for the lower strips and birch for the upper ones.
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