| 摘要 |
<p>Walls for absorbing airborne sound are made of massive material, such as brick, concrete, agglomerate, etc. and lined with a layer of porous, low density from covered by a trellis or lattice. The foam contains earth or compost material as a filler and absorbs moisture to provide support and nourishment for the runners or roots of plants which flourish on the trellis face. Pref. the foam is made of a resin which is horticulturally inert or which can progressively be consumed and replaced by the plant root system. Foams are specifically based on polyurethanepolymethylene-ureas, polybutene -sulphone or phenolic resins partly filled with compost, clay, trash, vermiculite expanded schist and planted with hedera, lonicera haponical, hypericum, wysteria, passiflora or pachysandra plants. Lighter, cheaper and more compact than use of massive banks or walls, easier to control than bushes or hedges. Pref. the screen involves twin walls back-to-back with an intermediate alley of air several metres wide and planted on the external faces of the two walls suitable for contg. sound alongside motorways, railways etc.</p> |
