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TABLE 3:
REQUIREMENTS WITH RESPECT TO COMBINED PHYSICAL AND CHEMICAL
ATTACK (HDPE GEOMEMBRANES)
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Property
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Characteristic
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Standard Values
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Test methods, Testing Regulations
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Change in tensile strength.
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After 112 days of immersion residual tensile
strength must be ³90%.
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Test as in pin impression test following DIN
53449 for the evaluation of environmental stress cracking, ball
or pin impression method, see Appendix A.
The relative residual tensile strength is the ratio of
the tensile strength of the immersed, pin-tested sample to the
tensile strength of the sample that has only been pre-immersed
and not pin-tested.
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16. Long
term performance of the weld seam
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Still to be determined
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Still to be determined
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Still to be determined
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17. Stress crack resistance of the weld seam
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Still to be determined
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Still to be determined
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Still to be determined
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18. Internal pressure creep test; time-dependent
creep strength of pipes
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Reference stress-time curves
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An extrapolation of the reference stress-time
curves obtained on the basis of DIN 8075 at higher temperatures
(eg 60° C, 80° C) must indicate that no failure is to be expected
at a strees of 5N/mm2 at 40° C in years (3.5 x 105
hours). For extrapolation see DIN 16887.
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Long-term internal pressure test in accordance
with DIN 8075 on pipes made from the same resin as the geomembrane.
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