Civil Engineering Reference
In-Depth Information
CE-marking also ensures that the products and systems sold are certified
as safe (i.e. in terms of release of dangerous substances and reaction to fire)
and consistent (i.e. certified under a factory production control system to
deliver a quality assured product). This is set out in EN 1504-8, covering
quality control and evaluation of conformity for the products and systems.
The most important aspect for the specifier or end user is the performance
of the product or system in service. The specifier must be aware that the
performance standards give a minimum level of performance, below which
the product will not be 'fit for purpose' and therefore will not carry a CE-
mark for the repair method. While this minimum performance may be
suitable for a 'general' intended purpose, it may not necessarily be adequate
for all applications.
When the appropriate repair methods have been selected, the relevant
performance requirements can then be built into the specification for the
works. Traditionally, full and detailed performance specifications have been
needed to prevent unsuitable products being used. EN 1504 overcomes this, as
the CE-marking process ensures that only suitable repair products and systems
are available to satisfy the various methods. The specifier need only quote in
the specification that a product should be CE-marked for the required method
(e.g. Method 7.2
Replacing contaminated or carbonated concrete
).
In reality, the EN 1504 specification process is slightly more complicated.
Parts 2 to 7 of EN 1504, which contain the performance requirements,
prescribe minimum performance acceptance values for specific critical
properties of the products and systems. Each of the Parts lists three
classifications of performance requirement:
• All intended uses - minimum performance values that every product
must meet for the particular method, including physical and chemical
properties, quality control and environmental issues;
• Certain intended uses - recommended minimum performance values for
one or more additional tests that may be called up by the specifier for an
unusual or difficult repair situation;
• Special applications - recommended methods of test, with no
recommended minimum performance values, that may be called up by
the specifier for a very unusual or difficult repair situation and are found
in the informative Annex B to the performance standards.
Use of EN 1504 in a specification is best illustrated by an example, such
as for Method 7.2 above.
Table 11.6
is an extract from EN 1504-3, listing
the performance requirements for four strength classes of mortar (Classes
R1 to R4) and corresponding performance requirements for all intended
uses.
Depending on the particular project, the engineer may decide that the
repair mortar should be stronger than a class R4 mix in
Table 11.6,
to match
the strength of the existing concrete. The specification for Method 7.2 could
