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 European Standards EFCA have observer status on TC 104/ SC3 for the development of
new European standards for admixtures and co-ordinates input by
national associations to their mirror committees. EN 934 is a series
of standards covering admixtures for concrete, mortar and grout.
These are complimented by the EN 480 series covering test methods
for admixtures. EN 934-1 covers 'Common Requirements' for all admixtures and will include the 'General Requirements' that are currently in Table 1 of the other parts of EN 934. It will also have requirements to confirm that admixtures do not have any enhanced corrosion effects on embedded steel. Eventually EN 934 part 1 will be extended to include admixture related requirements resulting from mandate M136 on concrete in contact with drinking water and also any requirements coming from the mandate M366 on Dangerous Regulated Substances. Publication of EN 934 part 1 will require the revision of parts 2 to 5 to remove conflicting clauses and references. EN 934 parts 2, and 6 for Concrete Admixtures have undergone amendment to take account of comments received as experience was gained following their initial publication. There is a request from TC 104 to make a further amendment to relax the requirements on the use of reference cement, especially for Factory Production Control (FPC). EFCA is about to make a proposal on this for consideration at the next SC3 meeting. A committee draft covering revision of EN 934-2 consequent on the publication of EN 934-1 has been circulated for initial comment by the SC3 secretary. EN 934 part 3 for Mortar admixtures was published in 2003 but did not come into use till 2005. Several manufacturers then found that it was unrealistically difficult to meet all the requirements in the standard with a single mix and a request was made to SC3 tor some amendments. SC3 requested that EFCA investigate further and come up with amendment proposals. This is in hand with EFCA members undertaking testing to the draft proposals before they are submitted to SC3. EN 934 part 4 on Grouts need amendment as a result of the revision of EN 445 and 447. EFCA has made proposals to SC3 and these have been agreed. A revised draft of EN 934-4 should go out for vote later in 2007. EN 934 part 5 for Sprayed Concrete passed formal vote in 2004 but it was then found to have serious editorial errors and therefore not published. It is now out for a second CEN vote under the fast track UAP system and it is hoped that it will be published later in 2007. EN 480 series. This series has been amended, mainly to take account of editorial changes as other standards have been published. Technical changes were made, especially to part 1 reference concrete with respect to the cement and the aggregate grading. EN 480-10 on chloride determination does have some technical changes outstanding. EFCA has made proposals and it is hoped that the amended document will go out for vote later in 2007. EN 480-14 on testing for effect on corrosion susceptibility has been published. The requirements for corrosion appear in EN 934-1.
This TG is producing draft procedures for assessing release of substances from concrete. The methods are very similar to those being proposed by TC 164/SC 3/AHG 6 for drinking water. EFCA has direct representation on this committee and has had changes made in relation to admixtures. As a general principle EFCA would prefer to see the TG 6 and AHG 6 documents aligned so that only one set of tests is necessary to get approval to the two mandated requirements. Self-Compacting Concrete The EFCA TC has played a leading role in initiating and contributing to the European Joint Project group producing the new Guidelines and a Specification for SCC. "The European Guidelines for Self Compacting Concrete" represent a state-of-the-art document addressed to those specifiers, designers, purchasers, producers and users who wish to enhance their expertise and use of SCC. These guidelines and are available for free download on the publication page of this web site. The test methods detailed in the European Guidelines have now been taken forward to CEN TC104/SC1/TG 8 and are being drafted into EN standards. EFCA is monitoring this through its involvement in national CEN mirror committees. TG 8 is likely to request the 2007 meeting of TC 104 to allow these draft standards to go forward for vote later in 2007. The specifications detailed in the European Guidelines have now
been taken forward to CEN TC104/SC1/WG 16 and are being drafted
into EN standard format. EFCA is monitoring this through its involvement
in national CEN mirror committees. WG 16 will report progress at
the 2007 meeting of TC 104/SC 1 but they are not ready to take them
forward to CEN enquiry. |
© EFCA 2007 |
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