| 摘要 |
Glued wooden beams intended particularly to concrete formwork in building and civil engineering. The cross-section of the beam has the shape of a rail and comprises a massive top boom (1) and a large bottom boom or footing block having a lower mean thickness (2). The single or double web (3) is comprised of plywood of which both thread directions of the plies are at 45<o> with respect to the booms. In the case of a double web, the two planks may be parallel or converging upwardly, the interval being either empty or filled with expanded synthetic material.
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