Preface

Author(s): Joaquim A.O. Barros
Paper category: Conference
Book title: 8th RILEM International Symposium on Fiber Reinforced Concrete: challenges and opportunities (BEFIB 2012)
Editor(s): Joaquim A.O. Barros
Print ISBN: 978-2-35158-132-2
e-ISBN: 978-2-35158-133-9
Publisher: RILEM Publications SARL
Pages: xxiii
Total Pages: 1
Language: English

Abstract: 
Fibre reinforced concrete (FRC) is a cement based material reinforced with discrete fibres that has been used for more than 40 years in the construction industry by mixing or spray-up process. By restraining the crack opening propagation, fibres increase the post-cracking residual strength of cement-based materials, providing significant increase of load carrying and energy dissipation capacities, mainly when the structures have high degree of support redundancy.

Flooring and tunnelling have been the major part of FRC applications, but in the last 20 years FRC is becoming gradually used for the development of innovative structural systems through partial or total replacement of conventional reinforcement. FRC is also gaining an increase role on structural rehabilitation, being integrated in competitive and sustainable strengthening techniques. Steel fibres have been the most used, but synthetic, natural and hybrid systems are proving to be competitive alternative solutions.Nano fibres and textile systems are also widening the potentialities of FRC. The advances in the mixing design methods and the availability of high performance superplasticizers and admixtures that allow the development of FRC of self-compacting requisites and ultra-high fluidity are providing new opportunities for the innovation in the Civil Construction Industry. The continuous growth of knowledge of the fibre reinforcement mechanisms is supporting the development of new generation of FRC with tensile strain-hardening character, with properties that can be engineered in order to fit certain design purposes, such as durability, integrity and outstanding capacity of energy dissipation. The use of recycled fibres is also being explored for infra-structure applications.
These advances on FRC from the material and technological perspectives are being complemented by the development of more reliable design guidelines and constitutive models. For the first time, the CEB-FIP Model Code has dedicated two chapters for FRC, covering the material characterization and design approaches. This is a significant step towards a more reliable and rational use of FRC, which is expected to enlarge the applicability of this extraordinary composite material.

However, some challenges still exist in the technology, design and quality control. The possibility of using fibres of different material properties and geometric characteristics demands for rational methodologies that correctly explore the optimum phases of the reinforcing mechanisms of these fibres. A continuous effort should be done on the reliability of the design guidelines, by considering the influence of fibre distribution and orientation. The bridge between stress-crack width and stress-strain design formats requires a simple but credible methodology. The definition of the most appropriate test setups for the material characterization and to provide data for the development of constitutive models for design guidelines and advanced FEM-based analysis is not yet well consolidated. The quality control tests also require deeper discussion in order to adequately define those that are the best representative of different FRC applications.

These and other opportunities and challenges of FRC are discussed in these proceedings, which include 125 papers from authors coming from 36 countries and 123 institutions. On behalf of the Organizing Committee of BEFIB 2012, I would like to express our deep gratitude for the valuable contribution of the members of the scientific committee. The support provided by the private sponsors and the collaboration of non-profitable institutions are also gratefully acknowledged.

Joaquim A.O. Barros, Chairman of BEFIB 2012

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00