| 摘要 |
A reinforcement includes two parallel walls formed with braces arranged along two orthogonal directions, the walls being spaced apart by tie rods. The structure further includes on at least one of its formwork surfaces a permeable structure for retaining aggregate and allowing excess water of cast concrete to escape. According to the invention, at least one of the parallel walls includes two mutually independent grates, one the grates being associated with the other wall by a first set of tie rods, and the other of the grates being associated with the other wall by a second set of tie rods, independent of the first set. When the grates are displaced in opposite directions along an axis parallel to the plane of the grates, the spacing between the walls is modified. |
