GB696938A - An improved reinforcement for prestressing concrete and process of manufacturing prestressed concrete with it - Google Patents

Abstract

696,938. Reinforced concrete. BAKKER, J. Jan. 30, 1952 [Dec. 13, 1951], No. 2432/52. Class 20(iv) Reinforcement for prestressing concrete consisting of a part subjected to adhesion of the concrete and brought under tensile stress, and a part insulated against adhesion of the concrete and brought under compressive stress, which parts are mutually connected in a disconnectable manner at the ends, so that after embedding the reinforcement in the concrete and the setting of the concrete, this latter can be prestressed by the part under tensile stress by disconnecting the connection between the two parts, is characterized in that the two parts, of which at least one is subdivided into two or more elements, are mutually connected in an axially displaceable manner and lie, alternating in a definite sequence, with their axes in a single flat plane or symmetrically with respect to a single flat plane, besides one another. Several forms are described; in that shown in Fig. 1 for example, the compressive stress elements 1 are wholly en circled by corrugated plates 3, 3a, which have other portions engaging longitudinally-spaced parts only of the tensile stress elements 2. In Fig. 7, 'the compressive stress elements 1 'are completely shrouded by curved plates 13, 13a having ears which engage between tensile stress elements 2, these latter being engaged by spaced oval metal rings 14. In Fig 10 the compressive stress elements 1 are completely encircled by wire wrapping 15, but the tensile stress elements 2 are only partially encircled. In Fig. 16 the tensile stress elements 2 pass through apertures in transverse strips 19 having central pyramidal portions 20, through apertures in which the compressive stress elements 1 pass, these elements being insulated from the concrete by the pyramids.