| 摘要 |
<p>A heat-insulating lightweight concrete for encasing a pipe consists of in percentages by volume 30 to 50 of pumice, expanded clay or porous lava having a grain size of 10 to 50 mm. and 15 to 25 of the same material having a grain size up to 10 mm., 10 to 25 of flakes of polystyrene, cork or a cellular plastic, 10 to 22 of cement, and up to 5 of fibrous glass, asbestos, wool or wood.</p> |
