|
Press Releases
November 2007
February 2009
NEW BRITISH STANDARD
November 2007
BS EN 13808:2007
Framework for Specifying Cationic Bituminous Emulsions
Introduction:
In order to ensure freedom of trade across Europe, the European
Committee for Standardisation has been producing a raft of
harmonised standards for bituminous binders. As part of that
programme, a new standard for Cationic Bituminous Emulsions has been
produced and is being introduced into all EC member countries.
The standard has been published in the UK in 2007 as BS EN
13808:2007
The Framework Specification:
This specification does not purport to be a performance
specification, but purely lays out a framework for identifying, or
specifying, characteristics of cationic bituminous emulsions.
The framework consists essentially of classes or levels of
performance for designated properties, which are applicable to any
emulsion type. It looks at the characteristics of the emulsion as
supplied, the characteristics of the recovered binder after
evaporation of the water and the characteristics of the recovered
binder after it has been subjected to an artificial ageing protocol.
What Emulsion Types does the new Specification cover?
BS EN 13808 does not specify how emulsions could or should be used;
it only provides a framework to identify properties which might be
important to the specifier or the installer. It is applicable to all
cationic bituminous emulsions for use in construction and
maintenance of roads, airfields and other paved areas. Emulsion
usage therefore will be determined by the classes for particular
properties.
What
will change?
Currently, non-modified emulsions are specified in BS 434 Part 1,
which covers both anionic and cationic applications.
Anionic Emulsions will continue to be specified through BS 434 Part
1
Cationic Emulsions will be specified via the new BS EN 13808:2007
Polymer Modified emulsions have never been subjected to British
Standards, and have always been classed as Proprietary materials,
developed for specific end uses. In the absence of a British
Standard, the Specification for Highway Works (SHW) Clauses 918,
919, 920 and 922 [2] and their Notes for Guidance [3] have specified
properties for emulsions for Slurry Surfacing, Surface Dressing and
for Bond Coats, Tack Coats and Other Bituminous Sprays. These
practices have served the UK industry successfully for many years
and it is anticipated that the same properties specified there for
polymer modified bitumen emulsions can be adopted to comply with BS
EN 13808.
Therefore, it is envisaged that existing UK Proprietary cationic
bituminous emulsions will continue to be supplied under their
current brand names and, in addition, they will be identified under
the grading and nomenclature described in BS EN 13808.
How will the new Specification be used?
BS EN 13808 covers the characteristics that may be called up in
emulsion specifications under two categories as follows:-
1)
Essential or Mandatory properties
– these are properties which the overseeing CEN secretariat deems to
be compulsory properties, which must be quoted. These include
On the Emulsion
i)
Viscosity
ii)
Adhesivity
iii)
Breaking Behaviour
On the recovered binder after evaporation
i)
Penetration
ii)
Softening Point
iii)
Cohesion (modified binders only)
On the aged binder
i) Penetration
ii)
Softening Point
iii)
Cohesion (modified binders only)
2)
Technical Requirements
– these properties are not mandatory, but have been found useful,
for example binder content of the emulsion.
It is important to understand that existing emulsion products will
not change upon the implementation of the new Framework, but will be
evaluated under the appropriate Classes from the Framework to
develop a specification. It is not the intention that end users or
specifiers/designers should select a theoretical specification from
the available classes, which could well result in unworkable and /
or unrealistic specifications, which may actually be detrimental to
the finished product performance.
Quality Assurance (BS EN 13808 Annex ZA)
BS EN 13808 contains a requirement for ‘Evaluation of Conformity’.
This details the steps which producers must take in order to
demonstrate conformity with the specification. Emulsion suppliers
will operate ISO 9001 system for quality management.
Initial type testing and Factory Production Control is determined by
EN 14733. After the declaration of conformity, Annex ZA states that
suppliers shall affix a CE mark. This is not yet a legal requirement
in the UK and suppliers may therefore apply a preparatory marking on
a voluntary basis.
When will it happen?
The UK industry will commence voluntary implementation from 1
January 2008
---------------------------------------------------------------------------------------------------------------------
February
2009
Update on BS EN
13808:2005 – Framework for Specifying Cationic Bitumen Emulsions
This Framework specification was
ratified in 2005, and is now in the Harmonisation stage.
Harmonisation is expected to take place in the near future to
coincide with the harmonisation of the new Framework specifications
for polymer modified bitumen and paving grade bitumen. The Industry
target is therefore to introduce the new Framework specification
across their cationic emulsion product ranges to coincide with this
event.
The UK Road Emulsions
Industry is using this intervening period to collate data using the
new test methods specified in BS EN 13808:2005 in parallel with the
existing UK test methods to ensure a smooth transition. As a result
of this work, a number of the test methods specified are currently
under review.
For further information please contact:
John Keayes
Consultant & Secretary
Tel: 01903 746584; Mobile: 07836 385543; web:
www.rea.org.uk |
Introduction