CONCRETE UNIT PROVIDED WITH A PLASTIC SURFACE LAYER; PROCEDURE AND PLATE STRUCTURE FOR MANUFACTURING SUCH UNITS; AND PROCEDURE FOR MANUFACTURING SUCH PLATE STRUCTURE

摘要

The concrete or reinforced concrete body with a plastic surface layer is characterised by that the plastic layer is made of a cross-linked, thermosetting, fibre-reinforced plastic plate, in which a metal wire is (or metal wires are) embedded containing barbs protruding into the concrete material or into the cemented layer in composite action with the concrete material. The procedure aimed at manufacturing such units is characterised by that a plastic plate is fitted at a given distance from the surface of the hardened reinforced concrete unit, especially prefabricated reinforced concrete unit, such as a pipe or tank, to be provided with a plastic layer, in a way that its protruding barbs extend into the gap between the unit and the plastic plate, and then the gap is filled favourably by injecting cemented afterhardening material into it. According to a different procedure the prefabricated reinforced concrete element, especially pipe (1) is placed with its front side on a favourably ring-shaped seal (2) situated on a horizontal production plane; in the unit a pipe- shaped plastic shell (5) with barbs (8) protruding from it is placed facing the internal surface of the unit, at a given distance (k) from it; the gap (7) between the shell (5) and the reinforced concrete unit is sealed with a favourably ring-shaped clamp (6) also fixing the shell (5); and the gap (7) is filled with cemented afterhardening material through one or more injection pipes (4) taken through the opening(s) made in the wall of the reinforced concrete unit at the bottom. The plate structure according , to the invention is characterised by that a metal wire containing barbs (8) is fitted into or/ and to the material of the fibre-reinforced cross-linked thermosetting artificial resin, the barbs (8) of which protrude from the surface of the plate structure facing the concrete or reinforced concrete unit to be connected to it. Such cylindrical plate structures are produced by coiling fibre fleeces impregnated with artificial resin; spraying sand and/ or cut fibre; coiling barbed (8) metal wire (16); finally fastening it by roving coiling.