French Standards for Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC)

Abstract

The French standard NF P18-470 related to UHPFRC specification, performance, production and conformity, published in July 2016, is a self-supporting document with distinct scope, however with the same outline as NF EN 206/CN, the French standard for ordinary structural concrete consistent to the European standard. Appendices detail test protocol adaptations as well as standardized methods associated to the determination of relevant UHPFRC characteristics. It covers both structural and non-structural UHPFRC. The French standard NF P18-710, published in April 2016, stands as a national complement to Eurocode 2 for the design of UHPFRC structures (both buildings and bridges). It covers UHPFRC with metallic fibers and characteristic compressive strength higher than 150 MPa. A third text (NF P18-451), to be finalized for public enquiry early in 2017, will complement the standard for execution of concrete structures, NF EN 13670/CN. Consistently, the common rules for precast products (NF EN 13369) will be updated to introduce these UHPFRC standards. Technically, these documents are based on the French AFGC recommendations on UHPFRC (revised in 2013) and technical feedback of 20 years of UHPFRC projects and realizations. However, significant additional precisions have been formally provided for clarification and easier implementation in a contract frame, among others: design to withstand fire and earthquakes, durability performance and design, classification of the material (based on compressive strength, tensile constitutive law, type of fibers ensuring sufficient ductility, possible thermal treatment, consistency at the fresh state and possible improved durability indicators), as well as formwork features and casting/post-casting operations requiring specific care in the case of UHPFRC, and geometrical tolerances. Complying with these documents shall help keeping the quality of UHPFRC realizations and promote their widened acceptability.