Mechanical performance of HDPE geomembranes seams after sunlight exposure

Abstract

Geosynthetic materials are increasingly used in solid waste landfills, but geosynthetic mechanical properties can change when exposed to sunlight. The experience with the evolution of mechanical performance due to UV radiation is not yet consolidated. Presently, at Laboratório Nacional de Engenharia Civil (LNEC) a research program concerning the evolution of the mechanical properties of HDPE geomembranes dual hot wedge seams exposed to sunlight during 12 years (expected service life of most Portuguese solid waste landfills) is under study. This paper presents the results of shear and peel tests in HDPE geomembranes dual hot wedge seams after 2, 3 and 5 years to sunlight exposure. The re- sults are compared, on one hand, with those of the same specimens exposed to sunlight but covered by geotextile, and on the other hand, with those of the same specimens not exposed to sunlight. The change of tensile properties of cover- ing geotextiles, after 3 years of sunlight exposure, is also presented. The analysis of the obtained results showed that the mechanical properties of the geomembrane seams were not affected significantly for the sunlight exposure until five years.