Grid tray for use in the reinforced concrete construction

摘要

The girder is especially for storey ceilings in semi-prefabricated building systems, using thin concrete slabs with lower chords and part of struts cast in, shuttering being removed shortly afterwards. Its upper chord is connected to lower chords alternately by struts rising and falling at an angle, forming a continuous zig-zag pattern of shaped steel. There are one or more struts at right angles to the upper chord between every two diagonal ones. Half of all the struts may be at right angles, and all struts may be formed from a single continuous piece of shaped steel. There may be paired vertical struts close together between the chords. A more favourable weight-to-shear-resistance ratio is achieved for the struts.