| 摘要 |
<p>A steel-reinforcement (28) in a draining unit (10) is partly open and/or a concrete body (12) on its underside or outer side to be linked to the underside is partly roughened up or profiled with a patterned depth between 2 and 50 mm. The steel-reinforcement is open/bare on the draining unit's underside turned away from a water course (18). It is also open/bare in the draining unit's side-walls pointing outwards.</p> |
