Press Release
                                                                                                November 2007

NEW BRITISH STANDARD
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

For further information please contact: 

John Keayes
Consultant & Secretary
Tel: 01903 746584; Mobile: 07836 385543; web: www.rea.org.uk