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Title:
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Ontwikkeling van een kortdurende test voor vormgegeven bouwstoffen, geïmmobiliseerde afvalstoffen en andere monolithische materialen
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Author(s):
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Published by:
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Publication date:
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ECN
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1998
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ECN report number:
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Document type:
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ECN-C--98-055
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ECN publication
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Number of pages:
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Full text:
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74
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Download PDF
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Abstract:
The tests of long duration, as specified in the Dutch Building MaterialsDecree, are inappropriate for a quick evaluation of the environmental
properties of construction materials and waste materials in the framework of
quality control. For monolithic materials and prefabricated construction
products the tank leach test is applicable. The mechanism of leaching, that
forms the basis for this test does allow a shorter testing cycle. However,
interference of initial effects not related to the dominant leaching
mechanism need to be taken into account. The present study deals with these
interferences, which can be reduced significantly by modifying the test
conditions. Attention has been given to such aspects as wash-off effects,
minimum volume for analysis, improved analytical sensitivity, avoiding
depletion, rapid water saturation, agreement with the NEN 7345 and
repeatability of a short test. For a wide range of materials the relation
between the short and the long test procedure is such that the proposed short
test can be used beneficially in material evaluation for quality control
purposes. Deviating leaching behaviour can also be identified by the short
test. Only in case of light weight concrete a higher leach rate is observed
resulting from the higher degree of saturation that is reached upon vacuum
saturation as compared to the standard procedure. This increase can, however,
be corrected for by means of a fixed correction factor. By combining the
short test and a better selection of crucial parameters by means of a pH
static leach test, a cost reduction relative to the complete NEN 7345 of at
least a factor 30 can be achieved. By presenting the results of the short
test in conjunction with the previously obtained NEN 7345 data (required by
the Building Materials Decree), it will be easier to recognise potential
deviations in behaviour, thus allowing corrective measures. Automation of the
short test has been shown feasible and contributes to a better repeatability
of the test. 25 refs.
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