Civil Engineering Reference
In-Depth Information
to cathodic protection; currently only proprietary systems are
available.
• 3.3 Spraying concrete or mortar
- while the performance of the finished
product is covered in EN 1504-3, another Standard specifically deals
with sprayed concrete generally: EN 14487-1.
• 7.3 Electrochemical realkalisation of carbonated concrete
- the
requirements are set out in a new performance standard specifically for
realkalisation and chloride extraction in reinforced concrete in CEN/TS
14038-1.
•
10.1 Applying an electrical potential
- the requirements are set out
in a new performance standard specifically for cathodic protection of
reinforced concrete structures in EN 12696.
Once the problem is defined and the extent of the damage known,
the designer and specifier can engage in an informed discussion about
the possible options for repair and the potential costs and appropriate
timescales.
Table 11.4
lists the six common options for repair found in EN
1504-9. An effective repair strategy will normally incorporate different
options for repair based on a range of factors such as the orientation of
the structure (e.g. to the sea), its height above ground, variation in the
quality of concrete around the structure, the variation in the cover to the
reinforcement and many more.
The standard does not and could not give definitive guidance on the
durability of the various options, or the relative performance of the various
products available to meet the options, principles and methods, beyond
setting the minimum performance criteria.
11.5 Performance Standards (parts 2-7)
As noted above, while EN 1504-9 gives 'General Principles' for repair, the
main purpose of EN 1504 is as a product standard leading to 'CE-marking'
of products and systems that are suitable for the protection and repair of
concrete structures.
To achieve a CE-mark, products and systems have to reach minimum
performance standards for a range of engineering properties, related to the
method to be used (Table 11.5). For example, a surface protection system
for concrete, such as a film-forming paint, will have different performance
requirements depending on whether it is intended to protect against ingress of
chloride ions, reduce carbonation of the concrete, control moisture penetration,
or whether the paint is to be applied over active cracks in the concrete.
CE-marking is intended to deliver products and systems certified to meet
minimum criteria for one (or more) of the repair methods listed in Table
11.5 (e.g. a very high performance coating may meet or exceed the minimum
performance for several methods, yet a lower performance product may
only be CE-marked for one method).
