| 摘要 |
<p>The invention relates to a fire-resistant prefabricated steel beam arranged to act together with concrete as a load-bearing jointing construction for various slabs. The beam comprises two web portions and horizontally projecting flange portions extending beyond the web portions. To achieve a simple beam easy to install at least each web portion (2) with its horizontally projecting flange portion (1) is formed by an integral material strip so that the web portion (2) and the projecting flange portion adjoining it form a jointless entity and so that the web portion (2) is in a slanting position with respect to the flange portion. The web portions (2) are arranged side by side so as to slant towards each other and interconnected at edges closer to each other by means of a horizontal upper part (3). The edges of the web portions (2) farther apart from each other are interconnected by means of a plate (4) welded to the web portions. Openings (14) are formed close to the upper edges of the web portions (2) and/or in the horizontal upper part (3) to fill the space defined between the upper part (3) of the web portions (2) and the plate (4) with concrete in a manner known per se.</p> |
