Testing and Processing # 1982 York
Stress relaxation in PVC and PEH sewage pipes was measured for more than 10 years, and the relaxation data were extrapolated by means of the Findley creep model up to 50 years. The influence of pipe dimensions, as well as that of the degree of deflection in the pipe are being discussed. It has been observed that the final extrapclated relaxation modulus strongly depends on the time the relaxation measurements have been continued. Presumably long-term measurements lead to results with better relevance with oractice.
Author(s) : Koski
The ring stiffness of a new design ribreinforced uPVC sewer pipe is studied. Creep measurement for 1000 h gives a reasonable first approximate of long-term stiffness. Because of the specific creep behaviour of uPVC, the measurement for 10,000 h gives a higher estimated stiffness. Relaxation results on new pipes...