New semi-probabilistic design method for non-structural elements made of UHPFRC

Author(s) : S. Bernardi, V. Malik, S. Dobrusky, G. Chanvillard, S. Sakji
Paper category : Proceedings
Book title : UHPFRC 2017 Designing and Building with UHPFRC: New large-scale implementations, recent technical advances, experience and standards
Editor(s) : F. Toutlemonde & J. ResplendinoT.Ch.
Print-ISBN : 978-2-35158-166-7
e-ISBN : 978-2-35158-167-4
Publisher : RILEM Publications SARL
Publication year : 2017
Pages: 585 - 592
Total Pages : 8
Language : English

Abstract: Despite the fact that nowadays there many useful documents focused on designing UHPFRC, none of them sufficiently covers a domain of thin non-structural elements (façade panels, sunshades, etc). The French standard NF P18-470 describe a simplified constitutive law for thin elements, three back analyses methods for determining the constitutive law, and a few recommendations on general aspects. Unfortunately, the disunited paragraphs have made the design of thin elements an impractical option. As the result, product certifications for thin elements made of UHPFRC in France were evaluated and certified according to a brittle-failure design. However, the brittle failure is avoided by the fibers. The thin elements mainly used for architectural applications are predominantly loaded in bending. When cracking stress of UHPFRC is reached, the fibers bridge created cracks. Moreover, the elements may resist higher loading when they exhibit deflection-hardening behavior (higher amount of fibers). In the case of UHPFRC, an apparent size effect of thin plates is relatively high. Consequently, a special design method for thin elements should be used to cover all specific characteristics.
In this paper, a semi-probabilistic design method for thin UHPFRC panels (developed by a working group involving CSTB, precasters and contractors) is presented. The method introduces two partial factors to ensure the sufficient safety of designed structures. The partial factors are calibrated by a reliability-based code calibration method considering French loading conditions (NF EN 1991). The new design method with the calibrated partial factors allows better exploitation of UHPFRC without compromising the safety requirements prescribed by EN 1990.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00