| 摘要 |
A prefabricated composite beam formed from two strips of timber (1, 2) are joined by metal connectors (4), preferably constituted by a rod having helical fins (15), retaining a block (18) of mineral wool in compression between the timber strips. The block of mineral wool is somewhat elastic and exerts outwardly directed forces shown by the arrow (18) upon the faces of the strips (1, 2) with which it is in contact. The mineral wool provides shear resistance and minimises relative movement upon a shearing force, being applied between the timber strips, for instance a bending force imposed upon the beam. The metal connectors (4) may be positioned at an angle to the longitudinal axis of the beam, to provide additional shear resistance. Several beams may be joined together by a flexible web (23) which allows the assembly to be compacted for transport and storage and extended before use so that the flexible web is stretched out to a suitable distance for use as rafters, suspended ceiling beams or floors. A kit including mineral fibre insulation for inserting between the beams is described. |
