Morphologie und Bruchverhalten medienbeaufschlagter Überlappschweißnähte aus Polyethylen hoher Dichte
Flexible membrane sealing liners made out of high-density plastic polyethylene are used in Germany as a basis to deal with municipal solid waste in combination with a clay mineral seal in landfills. This is done per state guidelines subject to the Technical Instruction 'Municipal Waste'.
There is a weakness of the welding seams in the liners under long term stress. This is caused by aggressive media impact, as well as settlement and dehydration of the clay mineral seal in the landfill. The long-term behavior and failure mechanisms of the hot wedge overlap seam joints were tested to understand the effects of complex compositions of test liquids. These liquids contain leachates such as organic acids and phthalate, as well as the inorganic nitric acid, which has a strong oxidizing effect. The nitric acid only affected only a marginal reduction of durability compared to the test liquids containing organic acids. In contrast, the phthalate entailed significantly shorter periods of lifespan. Due to the morphological changes of the welding seams observed during the test period, several testing methods were used. In order to understand the reasons for failure and structural changes, light microscopy, scanning electron microscopy,infrared microscopy were conducted as well as thermoanalytical test methods.Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
landfill liner, stress cracking, overlap weld seam joint, long-term behavior, lea-chate, morphological changes, thermoanalytical test method, tensile creep test, fracture mirror, oxidation stability, crystallinity, selective etching, weld bead, path of crack
Institute / chair: Fachbereich Bauingenieurwesen der Technischen Universität Carolo-Wilhelmina zu Braunschweig
Technical consultant for expert services: Prof. Dr.-Ing. K.-P. Großkurth (Betreuer), Prof. Dr.-Ing. H. Schorn
Publication year: 2003
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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