Characteristics of six PVC-P geomembranes installed in reservoirs in Spanish Mediterranean Basin

This paper presents the results obtained from six polyvinyl chloride geomembranes (PVC-P) reinforced with a synthetic fabric, installed in irrigation reservoirs for a period between 18-31 years. The geomembranes studied are part of the waterproofing system of the following reservoirs – El Hondon de las Nieves, El Rollo, Pla Aceituna, La Caseta de Mira, El Cid-III y El Rabosero, all of them located on the Spanish Mediterranean County of Alicante. The following experimental tests and interpretation of results are provided: relative values accounting for loss of plasticizer, tensile characteristics, foldability at low temperatures, dynamic impact resistance, puncture resistance, reflected optical microscopy and scanning electron microscopy (SEM). Also, the identification of plasticizers in the geomembrane entails the performance of Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography (GC) and finally, Mass Spectrometry (MS) tests. For the samples analysed, the loss of plasticizers is significant, ranging from 70.9% to 84.3%. However, the tensile strength results, give evidence of its current regular waterproofing working performance in the reservoirs. The results obtained suggest that the durability of PVC-P geomembranes is function not only of the loss of plasticizers but also the state of the synthetic reinforced fibres.