GB893974A - Improvements in pre-fabricated, pre-stressed concrete elements - Google Patents

Abstract

893,974. Flooring elements. STRANGBETONG A.B. Nov. 2, 1959 [Dec. 22, 1958], No. 37130/59. Class 20(4) A prestressed concrete element comprises a substantially rectangular slab 6, Fig. 1, cast integral with one or more underlying girders 7 extending between opposite edges of the slab, the bottom surface of the slab being inclined downwardly at 8 in the directions of both said opposite edges so as to reach the plane of the bottom surface of the girder or girders 7, each of said inclinations being at a distance from the edge towards which it is downwardly inclined equal to at least twice and at most six times the total thickness of the element. Above each bottom surface 8, the upper surface may be stepped at 10 and downwardly inclined at 11 to a lesser degree than the surface 8, or the upper surface may be plane, Fig. 3 (not shown) or may be slightly downwardly curved towards the edge, Fig. 4 (not shown). In an exemplified application, two elements are mounted with their adjacent edges supported by an underlying beam 12, a transverse space being formed between the two steps 10, the inclined surfaces 11, the edges 13 and the top surface of the beam 12. Reinforcements 19 projecting from the beam 12 are bent in opposite directions and reinforcements 15 projecting from the steps 10 are joined by couplings 16. Further reinforcements 17 may be positioned, after which the transverse space is filled with mortar. The elements may then be covered by a continuous layer of concrete if desired.