| 摘要 |
<p>The noise screening wall is made of concrete (3) which is open-pored on the side from which the noise emanates, while the opposite side it is coated with a dense sealing layer (6). Tubes or other cylindrical units (4) themselves made of porous sound-absorbing material, may be embedded inthe porous concrete. There may also be panels (5) of porous material, alone or in combination with the tubular units. These embedded elements may be made of mineral wool, or porous foamed material, cast into the fresh concrete or inserted into hollow spaces when the concrete has set. There may be a load bearing reinforcing skeleton frame (2), of reinforced concrete. Sound absorption may be further increased by provision of a structured surface (7).</p> |
