| 摘要 |
<p>Sports surfaces are constructed by supporting panels of corrugated bonded asbestos board on wood or concrete joists set in compacted gravel, filling in the undulations with fine sand and with two-tier battens to support plane bonded asbestos boards normal to the corrugatedboards. Joints between adjacent superficial panels are sealed with neoprene rubber. Used in prepn. of surfaces which are less hard than concrete or clay, to reduce risk of muscular or tendon injuries to athletes.</p> |
