The aim of research is to study the specifics of combined antifiltration constructions made of geosynthetic materials. The article considers improved and new combined constructions of antifiltration screens for irrigation canals and storages of liquid wastes. Using experimental design and approximative formula for determine specific discharge of water, we obtained an empirical formula for estimating a discharge through small orifices in the screen of polymer geomembrane; the adequacy of values according to Fisher’s F-criterion was checked and significance was calculated by Student t-test. Laboratory study of one of the proposed constructions was conducted. Laboratory experiments result in establishing the efficiency of self-healing for damages (small orifices) in polymer geomembrane. The research showed that for bigger orifices in geomembrane the more effective regeneration occurred (when the diameter of damage orifice was 5 mm the efficiency was 25 %, and when diameter was 20 mm – 95 %). For small orifices the efficiency decreases, but in the under-screen base (under polymer geomembrane) the viscous gel of bentonite is formed which prevents further filtration of liquid providing total impermeability of the construction. According to experimental results it was established that Ca-bentonite increases in size without loading up to 12 times (from 2 mm before hydration to 24 mm after it). The obtained results are presented as a map of level zones using software “Statistics” and the relation of self-healing efficiency to damage diameter.
Keywords: regeneration, bentonite mats, experimental design, filtration, geomembrane, construction of coatings.
