Long-term performance of EPDM geomembrane in El Boquerón reservoir

Abstract

El Boquerón reservoir (Canary Islands, northern hemisphere) is waterproofed with an ethylene-propylene-diene terpolymer (EPDM) geomembrane (GM). To evaluate the durability of EPDM GMs in hydraulic applications, the characteristics of the EPDM GM (resin and additives) installed in the El Boquerón reservoir were followed for over 21 years. The results of this study are presented herein and show that, based on measurements of specimens from the north and south slopes of the reservoir, the orientation of the GM influences its ageing, with the north slope in the coronation or crest area ageing the most rapidly. Over the years, the El Boquerón EPDM GM oxidised, which may be the main cause of crosslinking in the EPDM. In turn, crosslinking could be the mechanism behind some of changes observed in the EPDM GM characteristics over time. In addition, some of the mechanical characteristics of the EPDM GM were influenced by the additives in the formulation; in particular, the loss and oxidation of paraffinic oils. However, despite the age-induced evolution of the mechanical and physicochemical characteristics of the GM, the El Boquerón EPDM GM, after 21 years of exposure, still satisfies the minimum requirements established by French standards for virgin GMs.

Durability of reinforced PVC-P geomembranes installed in reservoirs in eastern Spain

“…For PVC-P, several cases support this conclusion since more than 50% of the additive was lost but the geomembrane has not yet been removed. Moreover, some PVC-P geomembranes installed in Spain exhibited losses higher than 80%, but they still fulfil their working requirements in the reservoirs (Blanco et al 2013b;Noval et al 2014c). Nonetheless, it is important to stress that these geomembranes are reinforced with a synthetic thread textile.…”

“…Consequently, high-density polyethylene (HDPE) geomembranes began to be used in some waterproofed reservoirs in Castilla-León and the Canary Islands (Noval et al 2014a(Noval et al , 2014b.…”

“…Next, a move into the field of elastomers began with the appearance of ethylene propylene diene monomer rubber (EPDM), which contains a minimum number of double bonds in its side chain and is not attacked by atmospheric ozone (Noval et al 2014c(Noval et al , 2015Blanco et al 2015).…”

A review of the performance of geosynthetics for environmental protection

“…Both of these studies concluded by recommending that oxidized bituminous GMs not be left exposed after installation. Noval et al (2015) also recently studied the evolution over 21 years of an ethylene propylene diene terpolymer (EPDM) GM installed in a pond in the Canary Islands. After 21 years, the flow rate remained below 10 À6 m 3 m À2 d À1 .…”

Laboratory Study of the Ultraviolet Radiation Effect on an HDPE Geomembrane

“…Figure 2. Tensile behavior of the samples after UV fluorescent device exposure.Tensile properties were evaluated by Noval et al[37] for an HDPE geomembrane with 1.5 mm of thickness during 20 years of weathering exposure in the San Isidro reservoir in Spain. The resistance and elongation presented the same trend during the time examined.…”