Evaluation of long term stress crack resistance of corrugated high density polyethylene pipes

Abstract

The 100 year stress crack resistance of corrugated high density polyethylene (HDPE) pipes was evaluated using a 600 mm diameter pipe. The stress crack resistance (SCR) tests were performed on the finished pipe at the liner and junction locations. The notched constant ligament stress test was used for the pipe liner assessment. For the pipe junction, a new method was developed to assess the effects of the liner corrugation join geometry. The test media was water at different elevated temperatures to accelerate crack growth rate. Two extrapolation methods, Popelar's shift method and the rate processing method (RPM), were examined by comparing the predicted curve with experimental data. The results indicate that the RPM is a more reliable method, and has been adopted to perform the failure time prediction at 23°C. The predicted time was found to exceed 100 years at the stress level of 3·4 MPa. Based on the test results, specification for 100 year stress crack resistance of corrugated HDPE pipes was established.

Keywords

HIGH DENSITY POLYETHYLENE STRESS CRACK RESISTANCE LIFETIME PREDICTION CORRUGATED PIPE RATE PROCESSING METHOD POPELAR'S SHIFT METHOD

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References

‘Standard specification for corrugated polyethylene pipes, 300- to 1500-mm diameter’, AASHTO Designation: M294.

Hsuan

Y. G.

and McGrath

T. J.

: ‘HDPE pipe: recommended material specifications and design requirements’, NCHRP Report 429, Transportation Research Board, National Research Council, Washington, DC, USA, 1999.

Hsuan

Y. G.

and McGrath

T. J.

: ‘Protocol for predicting long-term service of corrugated high density polyethylene pipes’, Technical Report, Florida Department of Transportation, USA, 2005.

Trankner

, Hedenqvist

and Gedde

U. W.

: Polym. Eng. Set , 1996, 36, (16), 2069–2076.

Hsuan

Y. G.

and McGrath

T. J.

: Proc. Plastics Pipes XII Conf., April 2004, Baveno, Italy, Plastics Pipes Conference Association, CDRom.

Hsuan

Y. G.

, Gurian

and Zhang

J.-Y.

: ‘Factors affecting the stress crack resistance of corrugated HDPE pipes’, Transportation Research Board of the National Academies, Washington, DC, USA, 2007.

‘Florida method of test for determining slow crack growth resistance of HDPE corrugated pipes’, Designation, FM 5-572.

Popelar

C. H.

, Kenner

V. H.

and Wooster

J. P.

: Polym. Eng. Set , 1991, 31, (24), 1693–1700.

Hsuan

Y. G.

and Zhang

J.-Y.

: J. Transport. Res. Board , 2005, (1928), 221-225.