| 摘要 |
1388411 Eyes and loops SHAKESPEARE CO 20 Jan 1972 [21 Jan 1971] 2830/72 Heading D1T [Also in Division E1] Reinforcing members for use in prestressed concrete are made up from resin-impregnated glass fibres in the shape of an endless loop Fig. 3 or a loop with a central, taped together length, Fig. 4. Each loop or turn is reinforced by further layers of resin-impregnated glass fibres, e.g. 62, or by a metal thimble 33. The loops or turns are run around blocks 42, Fig. 6, which may be peripherally grooved or otherwise shaped (see Figs. 9-15, not shown). A number of reinforcing members can be connected together in the formation of a prestressed slab, as shown in Fig. 24. The members may be used before the resin has completely set, to provide more flexibility and latter bond with the concrete. Various ways of fixing the members at their ends in moulds are described. To secure the reinforcing lengths of glass fibre at a loop or turn, they are resin-bonded, e.g. between thimble and loop, and compacted by wrapping around with plastics tape or using a split metal mould. The reinforcement can be in the form of a roving and can also be secured to the loops by winding on impregnated end rovings. |
