| 摘要 |
A concrete mass has an elongate metal insert (11) embedded therein, the outer surface of the insert having a recess (14) therein by which the insert is keyed into the concrete, and the inner surface defining an upwardly facing T-slot (15) which contains a fastener retaining member (17), for example, a rail fastener retaining block or bolt. With the invention, a sleeper can support a rail the transverse position of which is adjustable by sliding a rail fastener retaining block (17) along the T-slot (15), and, after final positioning, locking in position by insertion of a grout in the T-slot. |
