A High-density polyethylene has been used for buried plastic pipe production for over a decade. The structural performance of these pipes mainly depends on the viscoelastic properties of using materials. The aim of this study is to determine the creep behavior of PE100 material under constant tensile and flexural stress within 24 hours. In both tests, large deformation occurs within the first 1000 seconds and then very little or no deformation is observed. Primary and secondary creep stages have also been observed. At highest stress level, maximum strain is 5%, approximately.
At the flexural creep experiments, modulus of the material has been obtained from total deflection value at the end of 24 hours by using three point bending experiment under constant load. Large deflection occurs within in first 1000 seconds, after that, continues to increase slowly. Maximum strain is about 2%. The material exhibits linear viscoelastic response to 8 MPa stress level.