Abstract The current study addresses the cracking and self-healing capacity of Geosynthetic clay liners (GCLs) subjected to drying and wetting in a divalent salt solution. Commercially available GCLs, initially saturated under a load of 3.92 kPa, were stepwise dried for different durations in an oven at 30 °C and rewetted afterwards in deionised water and divalent salt solutions (CaCl2) of different molarities (0.05 mol/l, 0.5 mol/l and 0.05 mol/l prehydrated). The evolution of cracks and their patterns were studied by analysing X-ray images. In parallel, the water retention behavior was tested on the raw bentonite using micro-cells and a chilled-mirror hygrometer. The morphology of the crack patterns in the GCLs was highly affected by the pore fluid, which was reasoned by reduced tensile strength caused by the salt induced aggregation. The ability to retain water at a given suction was found to be higher for the samples subjected to CaCl2-solutions in comparision to the sample saturated with deionised water. However, a calculation of the osmotic suction caused by the additional CaCl2 in the porewater shows that the matric suction of the samples subjeted to CaCl2 decreases. The crack intensitiy factor (CIF) followed a similar trend and three different drying regimes were identified.

中文翻译：

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在 CaCl2 溶液中干燥和润湿的 GCL 中的吸力和裂纹扩展

摘要 当前的研究解决了在二价盐溶液中干燥和润湿的土工合成粘土衬垫 (GCL) 的开裂和自愈能力。市售的 GCL 最初在 3.92 kPa 的负载下饱和，在 30 °C 的烘箱中逐步干燥不同的持续时间，然后在去离子水和不同摩尔浓度（0.05 mol/l，0.5 mol）的二价盐溶液（CaCl2）中重新润湿/l 和 0.05 mol/l 预水合）。通过分析 X 射线图像研究了裂纹的演变及其图案。同时，使用微池和冷镜湿度计对原始膨润土的保水行为进行了测试。GCL 中裂纹模式的形态受孔隙流体的影响很大，这是由于盐诱导聚集导致拉伸强度降低所致。发现与用去离子水饱和的样品相比，经受 CaCl 2 溶液的样品在给定吸力下保持水的能力更高。然而，由孔隙水中额外的 CaCl2 引起的渗透吸力的计算表明，受到 CaCl2 影响的样品的基质吸力降低。裂纹强度因子 (CIF) 遵循类似的趋势，并确定了三种不同的干燥方式。