| 摘要 |
<p>In E-section building blocks which form sound-screening walls; sound absorbers are placed in the sound chambers in the upright and cross bars of the E outline. The sound absorbers are of foam plastic, and plug the mouths of the sound chambers without filling them completely. The sound absorbers pref. bear short surface ribs, arranged in a patchwork, with the ribs of neighbouring patches orthogonal. Each plug is made in two pieces of foam plastic with a stiffening plate between; the building block is grooved to receive the edges of this plate. The concrete is pref. pumice or foamed slag concrete, and the foam plastic polyurethane.</p> |
