| 摘要 |
<p>In a concrete-wrapped pipe having an inner water-impermeable resinous coating, the concrete wrapping is formed with a continuous inner portion covering the resinous coating and a helically slotted outer portion forming a helical wrap, the helical slot extending at least to the depth of a mesh reinforcement embedded in the concrete. The concrete wrapping serves as a water-permeable impact resistant barrier while permitting limited bending of the pipe.</p> |
