ABSTRACT
The essential features of the pretensioning of concrete members were described in Chapter 1. The anchorages used to maintain the tendons in tension until the concrete has hardened sufficiently must be reusable and the commonest system is a single barrel-and-wedge arrangement, shown in Fig. 8.1. Once the tendons have been tensioned to the required level, the jack is released and the wedges lock against the sides of the tendon and the barrel as the tendon contracts. The barrels bear directly against an anchor block which transmits the tensioning force via the prestressing bed to the other end of the tendon.
