Precast reinforced concrete permanent beams - are tee sections with slender flanges or hollow webs for longer spans

摘要

Precast reinforced concrete permanent forms (16) are for beam and slab deck construction, bridges and industrial shed roofs, and are designed to reduce site shuttering and shoring whilst reducing section weight to optimise cranage and transport costs. In their simplest form they constitute two beams with slender flanges (10). These latter abut when the beams are installed to form a bridge deck to provide a permanent shutter to the soffit of the slab (4). Pref. for longer spans the web itself is hollow. Multiple web units can be used. Areas of bottom flange (1) are provided say at supports for continuous spans. The units are designed to bear self weight and that of the in situ concrete, exposed stirrups and slab reinforcement (9) ensuring composite action of the integrated precast and in situ concrete elements.