PRESTRESSED CONCRETE ROOF-CEILING CONSTRUCTION WITH FLAT SOFFIT

摘要

The indirectly prestressed concrete roof-ceiling construction is prefabricated element for constructing industrial large-span buildings. The construction comprises distinctly wide and thin concrete soffit plate (1) and upper concrete girder (2), of the inverse "V"-shaped cross section, interconnected by slender steel pipe-rods (3) that are used to stabilize the upper girder (2) against lateral buckling and to prevent parts (1) and (2) to get closer or apart each to another. Prestressing of the soffit plate (1) causes compression in the upper girder (2) which passively (indirectly) pushes the ends of the construction, acting on some eccentricity over the centre of gravity of the cross section, causing rotation of its ends bending in that way the soffit plate upwards. There are two efficient methods of prestressing these constructions.