Testing Specification Design # 1995 Edinburgh
At the International Conference on Plastics Pipes W in Bath 1988, a paper was presented by the Author called : "Physical ageing of buried PVC sewer pipes as affecting their long-term behaviour". The tests performed on constantly deflected pipes referred to at that time had been running for approximately one year. Today, main results are available after nine years of testing. As expected this long-term study has given a more safe basis for the assessment of the behaviour of buried PVC pipes than presented seven years ago. In particular, the ageing effect of the amorphous PVC material has been confied , implying that the short-term ring stiffness of the pipe will increase in the course of time.