First ETAs and CE marking on quick setting cements
The initial setting time for these cements varies from one to ten minutes. These are special cements that are not covered by European standards. Therefore, a European Technical Approval (ETA) procedure is necessary for them before they can receive a CE marking.
Two types of rapid setting cements have recently obtained ETAs issued by CSTB; they are the result of two very different production processes. One is a hydraulic binder for which the raw materials are extracted from a single specific and homogeneous geological layer composed of clay and limestone and are burned in vertical kiln at a temperature below 1 200°C. The second type of cement, with quick strength rise feauture, was developed in research laboratories and patented during the 1990s. Its production consists of making a controlled mix of constituents and uses modern cement production technologies and tools.
These cements are designed for production of concretes, mortars and grout, and are used for various applications including finishing and repairing works requiring rapid hardening, sealing of cement mains or stopping of weak infiltrations of water in underground structures;, coating of embankments or slopes;, manufacturing of ready-mixed concrete and mortar. These cements are also attractive to the prefabrication sector for their quick set and strength rise features that can significantly increase the rate of construction of fabricated elements per form and per day.
CSTB's first action to satisfy demand from manufacturers, was to produce CUAPs (see inset). This work has particularly focussed (on, to, ??) to the specific characteristics of these cements: production of test operating methods suitable for rapid setting times, assesment of durability, etc. But CSTB experts have integrated existing standard requirements into CUAPs whenever possible, particularly EN 197-1 and EN 197-2, and EN 196 series standards for test methods.
After European Technical Approvals have been issued, CE marking of 5 cements started in 2007. The attestation system selected is the same as for current cements, namely 1+ (tests and certification of the product by an external institution). CSTB is an organisation notified for the corresponding services, and cooperates with the LEMVP (City of Paris Test Laboratory) and the ITC (Istituto per le Tecnologie della Costruzione). These two organisations have extensive experience in the certification of cement production plants and associated tests in France and in Italy.
*Common Understanding for Assessment Procedure
European Technical Approvals issued by CSTB are available on its Internet site: <//font><//u>http://www.cstb.fr/evaluations/ate/rechercher-un-ate.html
Link to the EOTA site to view the list of all valid European Technical Approvals : http://www.eota.be/
Two procedures for a European Technical Approval
The Construction Products Directive describes two procedures for issuing a European Technical Approval.
• The European Technical Approval may be produced based on a Guideline (ETAG) written by a European experts committee. This is the procedure adopted, for example, for issuing European Technical Approvals on anchors.
• If there is no guide, the European Technical Approval may be produced based on a CUAP*. It is written by one of the approval bodies. The CUAP and then the European Technical Approval project are transmitted to other European approval organisations for a joint adoption. The European Community chose the joint adoption procedure for production of European Technical Approvals on rapid setting cements.
Current cements under European standard
Cements form part of construction materials with one of the oldest histories of standardisation and marking. Scientific work led to the development of cements that we are using today in the XIXth century. Standardisation work in France began in 1919 and the NF VP marking was applied to all plants that requested it after the war in 1947.
More recently across Europe, standard EN 197-1 on current cements was adopted in 2000, followed by CE Marking based on this standard in 2001. The 1997 CE Mandate M/114 "Cement, construction lime and other hydraulic binders" identifies several categories of cements and binders for which harmonised European standards have been produced and particularly, in addition to ordinary cements already mentioned, special cements with low heat of hydration and sulphate resistant cements, aluminous cements, masonry cements, road binders and construction limes.
About fifty different cements and binders are covered by European standardisation at the present time. Some special binders are not covered by European standards, despite this long history in standardisation and marking. This is the case for quick setting cements.