Abstract The aim of this paper is to study the performance of plasticised polyvinyl chloride (PVC) geomembranes used in the rehabilitation of concrete and masonry dams. In such applications, the geomembranes are left exposed on the upstream face, without external protection, to environmental factors and weather conditions, especially to UV rays. Evaluation of the performance and the lifetime assessment of the geomembranes is very important from a managerial point of view. Therefore, the results from a 25-year ongoing study on the long-term performance of PVC-P geomembranes installed on the upstream face of Italian dams are presented. The sampled geomembranes have been subjected to physical and mechanical tests and the results interpreted with reference to the variation of plasticiser, tensile characteristics, foldability at low temperatures, volumic mass and water vapour permeability. In the analysed samples, the loss of plasticiser range from 14.83% to 21.86%. This decrease in plasticiser content resulted in slightly higher modulus and tensile strength. The functionality of the geomembranes was not affected, as evaluated also by on site inspection. On the basis of the experimental results, lifetime predictions of the exposed geomembranes using the function of the loss of plasticiser were made.

中文翻译：

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安装在意大利大坝上的外露 PVC-P 土工膜的寿命评估

摘要 本文的目的是研究用于混凝土和砖石坝修复的增塑聚氯乙烯 (PVC) 土工膜的性能。在这些应用中，土工膜暴露在上游表面，没有外部保护，环境因素和天气条件，尤其是紫外线。从管理的角度来看，评估土工膜的性能和寿命评估是非常重要的。因此，本文介绍了一项为期 25 年的关于安装在意大利大坝上游面上的 PVC-P 土工膜的长期性能研究的结果。取样的土工膜已经过物理和机械测试，结果参考增塑剂、拉伸特性、低温折叠性、体积质量和水蒸气渗透率。在分析的样品中，增塑剂的损失范围从 14.83% 到 21.86%。增塑剂含量的这种减少导致模量和拉伸强度略高。土工膜的功能没有受到影响，正如现场检查所评估的那样。在实验结果的基础上，利用增塑剂损失函数对暴露土工膜的寿命进行了预测。