Geoscience Reference
In-Depth Information
DURABILITY IN CE MARKING
The application standards stated above also contain a 'normative annex' on durability
in which the following situations are differentiated:
￿
The extent to which the geotextile is resistant to ultraviolet (UV) radiation. This is
tested in a “Weathering test” (ENV 12224) and is important to empirically deter-
mine how long a geotextile can be exposed to UV radiation before it is covered
by soil or water;
￿
The durability after installation of the geotextile.
RESISTANCE TO UV RADIATION
The Weathering test (ENV 12224) exposes a geotextile to a predetermined amount of
UV radiation with the strength established before and after the UV radiation period.
Depending on the result of the test and the required application, the UV exposure
times stated in Table B.2 reveal how long the unprotected geotextile may be exposed
to sunlight. Geotextiles not tested have to be covered with soil within one day after
placement, or placed deep enough in the water that they are no longer subject to UV
light exposure.
The text above is taken from the durability appendix of the CEN standards. Geo-
textile mattresses, tubes, bags and containers can normally be exposed for a long period
to sunlight. This is normally not the case for other systems, such like slope revetments,
filter constructions under water, etc. If required, the working method can be adjusted
to ensure that the geotextile is subjected to sunlight for only a short period of time.
DURABILITY AFTER INSTALLATION OF THE GEOTEXTILE
In the European standards for geotextiles two situations are distinguished:
￿
applications with a lifetime shorter than 5 years;
￿
applications with a lifetime of up to 25 years.
Table B.2 Maximum times that a geotextile may lie exposed on a construction site, depending on the
result of the 'Weathering Test' and the application.
Retained strength
(after exposure to test)
Maximum time of exposure
after installation
Application
Reinforcement or other
applications where long-term
strength is a significant parameter
> 80%
60% to 80%
< 60%
1 month a
2 weeks
1 day
Other applications
1 month a
2 weeks
1 day
a Exposure of up to 4 months may be acceptable depending on the season and on the location in Europe.
> 60%
20% to 60%
< 20%
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