Abstract: An outdoor aging test base for geosynthetics was established in Wuhan, central China to investigate the long-term aging performance of geosynthetics. Outdoor photo-oxygen aging tests for high density polyethylene (HDPE) geogrid have been carried out in the base. Test results show that in the initial nine months, the tensile strength of geogrid remains unchanged or even gets larger, while the corresponding strain at break decreases slightly, exhibiting hard and brittle trend due to secondary compensatory responses to the ultraviolet(UV) aging: UV provides the required chemical crosslinking energy, resulting in the polymer crosslinking reaction. Tensile strength of the geogrid increases by about 5% in the initial nine months, but decreases after the initial nine months. The long-term research results at the test base could provide first-hand data for researching the aging properties of HDPE geogrid.

Key words: outdoor test, aging, tensile strength, HDPE, geogrid