Key Parameters for Building Reinforcement with an UHPFRC Overlay

  • Raphaël Fabbri (Ecoles d’Architecture)
  • Jenine Principe (University of Naples Federico II)
  • Julien Derimay (LafargeHolcim)
  • Sebastian Bernardi (LafargeHolcim)


Among the various kinds of building materials, since the 20th century the reinforced concrete is certainly the most common. However, many concrete structures present risks linked to technical obsolescence and degradation phenomena which often require a refurbishment necessary to increase the structure load-bearing capacity. It has been already proven that the addition of an UHPFRC overlayer on a concrete existing section can improve the resistance and the durability of the whole structure, as long as a strong bond between the new layer and the concrete is provided. Starting from the experience gained from bridge and viaduct repair, this paper presents the key parameters to design an UHPFRC reinforcement cast on an existing concrete slab. The method consists in using a calculation tool for preliminary design developed by Atelier Masse and LafargeHolcim, that compute the gain of the bending moment capacity of a slab with and without an UHPFRC overlay. After having fixed a set of preliminary assumptions, the paper will describe the behaviour of the cross-section and the influence of the different parameters (existing reinforcement percentage, UHPFRC type, fiber content, thickness of the overlayer etc. etc.) on the bending moment capacity gain. The aim is to help the designer choosing the right project strategies in case of a concrete structure refurbishment.

Keywords: Refurbishment, UHPFRC overlay

How to Cite:

Fabbri, R., Principe, J., Derimay, J. & Bernardi, S., (2019) “Key Parameters for Building Reinforcement with an UHPFRC Overlay”, International Interactive Symposium on Ultra-High Performance Concrete 2(1). doi:

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Published on
01 Jun 2019