DEVELOPMENT OF A PREDICTIVE METHOD FOR ACTUAL SERVICE LIFE ESTIMATION OF THE ABOVE-GROUND PART OF A PILE POLYMER COMPOSITE PIPE IN THE SUMMER PERIOD IN EXTREME NORTHERN CONDITIONS

In this paper, the complex effect of ultraviolet (UV) radiation, temperature and humidity on the mechanical properties of glass and basalt-plastic pipes manufactured using wet cross-layer and
cross-winding technologies, respectively, was considered. It was shown that UV radiation is one of the key factors leading to degradation of the structure of polymer-composite materials (PCM) and,
as a consequence, affecting their performance in extreme Northern conditions in summer period. The reason for the change in the mechanical properties of PCM under the influence of UV radiation,
temperature and humidity is extensive erosion, leading to microcracking of the PCM matrix with the subsequent formation of volumetric defects. It was found that glass and basalt-plastic have the
same resistance to summer conditions of the Arctic and Subarctic climates, but fiberglass samples are more prone to water absorption. The obtained regression equations make it possible to accurately
predict the actual service life of the upper part of the PCM pile in natural Arctic conditions.