GeoEngineering Centre at Queen's-RMC, Queen's University, Kingston, ON K7L 3N6, Canada.
Soil Mechanics and Foundation Engineering Unit, Structural Engineering Department, Ain Shams University, Cairo, Egypt.
Waste Manag. 2019 Dec;100:18-27. doi: 10.1016/j.wasman.2019.08.028. Epub 2019 Sep 5.
The decrease in stress crack resistance (SCR) of geomembranes (GMBs) due to physical ageing is examined. It is shown that the SCR of a 1.5 mm high density polyethylene (HDPE) GMB immersed in municipal solid waste (MSW) leachate, deionized (DI) water, and air experienced a decrease to an equilibrium value, denoted herein as SCR, in a few months and then did not change for the remainder of a 116-month test. The same GMB was also immersed in basic mining pregnant leach solution (PLS) and brine and a similar decrease in SCR to SCR was observed in the first three months. For this GMB, SCR was about 50% of the initial SCR value (i.e., SCR ∼ 0.5·SCR) for all incubation fluids examined. It is then shown that this behaviour is not unique. Seven other high density polyethylene (HDPE) and one blended polyolefin (BPO) GMBs are shown to experience a decrease in SCR to 0.17·SCR ≤ SCR ≤ 0.56·SCR without any evidence of oxidative degradation. The magnitude of SCR is shown to be product specific. In contrast, the one linear low density polyethylene (LLDPE) examined exhibited no such physical ageing. The implications for designing with GMBs are discussed.
研究了物理老化导致土工膜（GMB）抗应力开裂（SCR）能力下降的问题。结果表明，在几个月内，浸入城市固体废物（MSW）浸出液、去离子（DI）水和空气中的 1.5mm 高密度聚乙烯（HDPE）GMB 的 SCR 会降至平衡值，即本文中称为 SCR，然后在 116 个月的测试剩余时间内不会发生变化。同一 GMB 还浸入了基础采矿富液（PLS）和盐水，在最初的三个月内，SCR 也观察到类似的下降到 SCR。对于这种 GMB，所有测试的孵育液中 SCR 约为初始 SCR 值的 50%（即 SCR∼0.5·SCR）。然后表明，这种行为并不是唯一的。另外七种高密度聚乙烯（HDPE）和一种混合聚烯烃（BPO）GMB 被证明会经历 SCR 下降到 0.17·SCR≤SCR≤0.56·SCR，而没有任何氧化降解的迹象。SCR 的幅度表明是产品特异性的。相比之下，所测试的一种线性低密度聚乙烯（LLDPE）则没有表现出这种物理老化。讨论了这对使用 GMB 进行设计的影响。
