| 摘要 |
A composite geotextile prod. partic. for drainage applications consists of at least one filtering sheet (5 or 7) and at least one drainage layer (3) in which is a network of mini-drains (1) consisting of multi-perforated, ringed, tubes laid parallel. Pref. the filtering sheet is made of polypropylene, HDPE, polyester or mixtures of fibre nonwoven and stitched with density 150-300 g/m<2> with pore size of 50-120 microns. The drainage layer is made of similar materials with a free space index of 85-95%. The mini draws consist of rigid PVC, HDPE or polypropylene perforated ring tubes, with compression resistance greater than 600 KPa.
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