The article "Lifetime assessment of exposed PVC-P geomembranes installed on Italian Dams," written by Daniele Cazzuffi (CESI Advisor) and Domenico Gioffrè (Professor of Civil Engineering and Architecture at the University of Pavia), was awarded as the best paper of the year 2020 by the Editorial Board of the prestigious ‘Geotextiles & Geomembranes’ journal. The 'Geotextiles & Geomembranes' journal is the most important international scientific journal in the field of geosynthetic engineering.
The deterioration of concrete and masonry dams is caused by the environment or by abnormal behavior of the structure itself. As a result of cracks in the concrete and loss of imperviousness, water infiltrates the dam body, and subsequent washing of fines may cause carbonation and clogging of the drains. This is a particularly crucial issue for dams in Italy. The aim of the awarded paper is to study the performance of plasticized 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 at the CESI Geosynthetics Laboratory and the results interpreted with reference to the variation of plasticizer, tensile characteristics, foldability at low temperatures, volume mass and water vapor permeability.
In the analyzed samples, the loss of plasticizer ranges from 14.83% to 21.86%. This decrease in plasticizer content resulted in slightly higher modulus and tensile strength. The functionality of the geomembranes was not affected, as evaluated also by onsite inspection. Based on the experimental results, lifetime predictions of the exposed geomembranes using the function of the loss of plasticizer were made.
Given the importance of the analysis carried out by Cazzuffi and Gioffré, the two authors will personally receive the award, which is given to the authors of the four best articles of the four-year period, at the next 12th International Conference on Geosynthetics, which will take place in Rome from 17th to 21st September 2023.