| 摘要 |
1440249 Walls and roofs K SCHADEN 18 June 1973 [21 June 1972 12 July 1972] 28802/73 Heading E1W The walls or roofs of a building or tunnel are provided with an inner facing of concrete laid over a plastics sheet which is initially placed against the wall or roof, and which has a number of protuberances directed towards the wall or roof from the main area of the sheet, these protuberances being hollow, generally cylindrical, but tapering inwardly towards the wall or roof, and open at both ends, allowing concrete to pass therethrough and contact the wall or roof. |
