What do EN 14889 and CE marking mean for fibre reinforced concrete?
Fibre classes, conformity systems and CE marking: a clear explanation of EN 14889 and the framework for structural fibre reinforcement in the Netherlands.
Anyone using fibres as reinforcement in concrete inevitably encounters the EN 14889 standard. This harmonised European standard consists of two parts: EN 14889-1 for steel fibres and EN 14889-2 for polymer fibres (synthetic fibres). Both set out the definitions, specifications and conformity requirements for fibres used in concrete, mortar and grout. Since 1 January 2007, CE marking in accordance with these standards has been mandatory for fibres sold on the European market.
Micro and macro fibres: Class I and Class II
EN 14889-2 classifies polymer fibres on the basis of their physical form and diameter. Class I covers micro fibres with a diameter of less than 0.30 mm, with subclasses Ia (monofilament) and Ib (fibrillated). Class II covers macro fibres with a diameter greater than 0.30 mm.
The distinction is more than a formality. Micro fibres mainly control plastic shrinkage cracks in young concrete but provide no structural residual strength. Macro fibres do: they are used where a residual flexural strength is required after cracking, and can therefore fulfil a structural function. Anyone considering fibre reinforcement as a replacement for traditional reinforcing steel therefore needs macro fibres or steel fibres, not micro fibres.
Two conformity systems
The standard has two attestation systems, depending on the application. For structural use, System 1 applies — the strictest regime: a notified body carries out type testing and takes samples at the production site. For general, non-structural applications, the lighter System 3 applies, with basic testing and documentation without certification of production control by a notified body.
Compliance with the standard gives a presumption of fitness for the applications stated on the CE marking. For structural fibre reinforcement, System 1 is therefore the signal to look out for.
CUR-Aanbeveling 111 as the Dutch assessment framework
Alongside the European CE marking, the Netherlands applies its own assessment framework for steel fibre concrete: CUR-Aanbeveling 111, "Staalvezelbeton-bedrijfsvloeren op palen: dimensionering en uitvoering" (steel fibre concrete industrial floors on piles: design and execution), in its revised March 2019 edition. The recommendation extends the standard calculation methods for structural concrete with calculation methods for steel fibre concrete, and serves as the framework for structural engineers and building control authorities.
For structural floors on piles, a fibre content in the order of around 35 kg/m³ is generally taken as a minimum; the exact dimensioning always follows from the calculation according to the recommendation. By way of comparison: steel fibre dosages for industrial floors typically range between 20 and 40 kg/m³, while structural synthetic macro fibres can suffice with just a few kilograms per cubic metre. You determine the correct value together with your structural engineer.