| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the entering of gravels, improve water absorption perfor mance, pressurizing resistance, shape keeping performance, flexibity, and freely correspond to a small aperture less than prevent thickness by weaving fibers on the surface of a spring pipe, followed by heating and close contact. SOLUTION: A suitable fiber material for a layer 2 braided of fibers is one having heat resistance resistant to the temperature of asphalt paving, waterproofness and excellent mechanical strength, and one brought into close contact with a spring pipe 1 through heat contraction and especially having a contraction rate of 5 to 50%, preferably 5 to 30%. For such a material, polyester resin fiber is suitable. The layer 2 made of fibers is in close contact with the spring pipe 1 through heat contraction or heat adhesion, the spring pipe 1 is not dislocated from the layer 2 generating no gap. Since the spring pipe 1 is in close contact with the layer 2 without adhesive, satisfactory water absorption performance is shown.</p> |
