2 сентября, 2015 
Malyar Steel wire and strand formed into cables is commonly used in the prestressing of concrete and in suspended or cable stayed structures such as bridges. In both cases it is sometimes necessary to splay the constituent wires or strands at the end anchorages in order to spread the load being transferred to the support material.
In cable-supported bridges this is achieved by splaying the strand ends into a conical socket which is then filled with molten metal. When the cable is tensioned the conically formed deflector is pulled into the socket and load transferred in compression by wedge action. In some cases (1) the molten metal has been replaced by a low viscosity two-part resin, usually a filled polyester for its speed of cure. This obviates the need for heating and enables the attachment to be formed on site. Although it has been argued that the frictional force between the strands and the anchorage is sufficient to retain the cable end in the socket, some interfacial bond is necessary otherwise the strands would pull out before the wedging action could develop. Similar techniques are now being considered for use in sleeve couplers designed to connect steel bars for the reinforcement of concrete (see Chapter 8).
Pourable epoxy resins have also been used to bed deflector plates and anchorage plates in certain special applications of prestressed concrete(7). One such example was a farm access bridge over the northern end of the Ml motorway. Following the discovery of cracking in some parts of the concrete box which formed the arch structure a strengthening method was sought which would not detract from the appearance of the bridge. A system of prestressing within the box was evolved but this required anchorages capable of providing adequate strength to spread the load within the corners of the bottom of the box. Hence the use of deflector and anchor plates bedded in epoxy resin.
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