GB642589A - A compound-reinforcement for concrete structures - Google Patents

Abstract

642,589. Reinforced concrete. BILLIG, K. May 5, 1947, No. 12074. [Class 20(iv)] A compound reinforcement for concrete structures comprising a preformed unit having a hole extending between opposite sides of the unit, at least one tensioned wire or cable threaded through the hole and grouting which has set after being poured into the hole and around the wire or cable, said grouting maintaining the wire or cable in tension and applying the pull of the wire or cable to the unit to maintain it in compression. In one form the reinforcement is made by mounting a series of high quality concrete flanged tubes 1 in coaxial alignment and threading steel wires 4, of high tensile strength, through them, the wires being positioned by drilled washers 5 so that their gravity axis and that of the tubes coincide. The ends of the wires are carried through wood blocks 7 and, at one end of the reinforcement, are secured in an anchorage block 10 by a wedge 12 whilst at the other they pass first through a collar 9 and are then secured in a similar block. The wires are tensioned by a jack which forces the collar 9 and the adjacent block 10 apart, a distance piece being inserted between them when the required tension has been obtained. The jack is then removed. Grout is now poured into the tubes through the holes 20 and after it has set sufficiently, the anchorages 10 are removed by sawing through the wood blocks 7. The reinforcement is used in the same way as mild steel reinforcement, the outside of the tubes being roughened tc give high bonding with the in situ concrete of the structure. Specification 561,135 is referred to.