A NEW MODEL FOR THE CALCULATION OF STRUCTURES AFFECTED BY DEF – APPLICATION TO A VIADUCT CASE

Author(s): O. Omikrine-Metalssi, B. Kchakech, S. Lavaud, B. Godart and F. Beauvallet
Book Title: RILEM International Symposium on Concrete Modelling - CONMOD 2014
Editor: Kefei Li, Peiyu Yan and Rongwei Yang
ISBN: 978-2-35158-139-1
e-ISBN: 978-2-35158-140-7
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 460-469
Total Pages: 10
Language: English

Abstract: Concrete construction is becoming increasingly complex and the importance of producing structures that are both cost effective and durable has never been higher. Therefore, an understanding of concrete durability is fundamental to establishing the service life of new or existing structures. However, for existing concrete structures, a significant number of bridges are at present deteriorated by chemo-mechanical processes known as Delayed Ettringite Formation (DEF). This phenomenon causes expansion of the affected concrete that generally leads to cracking and decrease of its mechanical properties. Therefore, these pathologies raise severe problems regarding serviceability, sustainable operation and structural integrity. Thus, it is necessary to provide predictive models able to re-assess the mechanical state of the affected structures. In this way, the chemo-mechanical modeling must be dealt with by considering the influence of humidity, stiffness reduction and stress in the development of expansion.

The elaborated 3D model was applied to a real viaduct affected by DEF. The displacements and stresses were computed thanks to the experimental data given by the in-situ measurements. The results highlight the relationship between the saturation degree and the expansion. Finally, comparisons between different calculations with and without considering the anisotropy of expansion and stiffness reduction are presented and discussed.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00