FLAT SOFFIT DOUBLY PRESTRESSED, COMPOSITE, ROOF CEILING CONSTRUCTION FOR LARGE SPAN INDUSTRIAL BUILDINGS

摘要

The construction is used in the construction of large span industrial buildings wherein cracks in the concrete are reduced and its deflection is controlled. It improves the aesthetic appearance of the roof-ceiling and reduces the heated volume. The construction comprises a wide and thin concrete Soffit plate (1) and a two-part upper steel construction (2), interconnected to plate (1) by means of vertical elements (3). The construction is twice prestressed by two independent methods. The concrete plate (1) is centrally prestressed in the mould (6) after the concrete has hardened, the upper steel construction (2) is prestressed by pushing apart by a wedge (7) at the midspan, after which the individual steel parts are connected. Prestressing of the Soffit concrete plate (1) eliminates or reduces cracks in the concrete, and the subsequent prestressing of the upper steel construction controls any deflections.