PVC - Pipes and Pipe Systems # 1988 Bath
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 compare with those on conventional smooth wall uPVC sewer pipes. Creep and stress relaxation in plastics are material properties.
Sewer pipes are developing towards lighter constructions. New product standards and test methods are needed. Practical and good experience of plastics sewer pipes of comparable materials is available since early 1960s. Some early results of laboratory tests help to build a bridge between the stiffness behaviour of traditional smooth solid wall pipes and new rib-reinforced constructions. New test data of new products is still necessary to confirm the quality.
Author(s) : Koski
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...