these side wall portions are designed and constructed as tee sections the segments 2 are separated from one another by transverse separations 4 the support wall portion 5 accommodates two reinforcement fibers 6 substantially parallel to the direction of the strand the reinforcement fibers 6 project from strand 1 the embodiment shown in fig4 comprises a connector 15 which adjoins strand 1 in the direction of the strand this connector 15 comprises two grooves 16 in which the projecting portions of reinforcement fibers 6 are arranged the connector is designed and constructed as a rectangular hollow section perpendicular to the direction of the strand the connector comprises in addition connection bores 14 which serve as a possibility of attachment or connection to a contact or bearing surface not shown the projecting portions of the reinforcement fibers 6 extending in groove 16 are clamped in the interior of the hollow section of connector 15 between an upper plate 18 and a lower plate 19 the force necessary for clamping reinforcement fibers 6 between upper plate 18 and lower plate 19 is produced by a fastening means 17 in the embodiment illustrated in fig4 the fastening means 17 is realized as a.