Preface

Author(s): D. Bjegović, H. Beushausen, M. Serdar
Paper category: Workshop
Book title: RILEM International workshop on performance-based specification and control of concrete durability
Editor(s): D. Bjegović, H. Beushausen, M. Serdar
ISBN: 978-2-35158-135-3
e-ISBN: 978-2-35158-136-0
Pages: XV - XVI
Total Pages: 2
Language: English

Abstract: 
The durability of reinforced concrete structures remains an aspect of great relevance to our society. Most countries worldwide are faced with a large proportion of their ageing civil and building infrastructure being in need of repair, which is related to significant economic burdens to national budgets. In many cases, premature deterioration of concrete structures can be linked to inadequate design methods for concrete durability as well as a lack of quality control during construction.

Traditional design and specification methods for concrete durability are based on prescriptive concepts, which result in material and cover depth specifications based largely on simplistic descriptions of factors such as exposure classes. Following this approach, durability specifications in most existing codes and standards are based primarily on establishing constraints to the material and mix proportions of the concrete, such as maximum w/b ratio, total minimum cementitious materials content, and minimum concrete strength. In this approach, design for durability includes the choice of exposure class and compliance with material requirements, concrete cover requirements, and placing, compacting and curing procedures. Notably, few of these requirements can be verified during actual construction.

However, many researchers and engineers argue that durability for a structure in a given environment is a material performance concept; as such it cannot easily be assessed through simple mix parameters. The prescriptive approach ignores, to a large extent, the different performance of the various binder types and of the mineral components added to the cements or to the concrete itself, as well as the type of aggregate, and does not allow to take into account the influences of on-site practice during the construction process. It also cannot explicitly account for a rational service life requirement. Performance concepts, on the other hand, are based on quantitative predictions for durability (or service life) from exposure conditions and measured material parameters. The resistance of the structure, measured through durability parameters of the actual concrete used, is compared against the environmental load. On this basis, deterioration of a structure during its lifetime is quantified using appropriate deterioration models. In this concept, the actual concrete properties, preferably measured in situ, are of critical importance. The main advantages of the performance approach to concrete durability design include that relevant material parameters can be specified and measured, which results in efficient quality control of the as-built structure and consequently in better durability properties, extended service life, and reduced need for costly maintenance and repair. The performance approach further supports innovation in material technology as it moves away from restrictive requirements for material composition and construction.

With this background in mind, RILEM TC 230-PSC was constituted in 2008 and grew to a membership of more than 45 experts from around the world. Several meetings took place over the years in Italy, France, the Netherlands, Germany, South Africa, Switzerland, and Croatia. The subject matter of the TC 230-PSC was to establish guidelines for the specification of the penetrability and thickness of the concrete cover, as a function of the exposure conditions and service life design, and for compliance control through suitable site and/or core testing. The development of guidelines for the application of suitable performance based approaches for concrete durability is an onerous task that will require further research into the calibration of suitable test methods and service life prediction models. The State-of-the-Art-Report on performance-based specification and control of concrete durability, which was prepared by RILEM TC 230-PSC should be published in book form in early 2015, and lays the foundation of such an undertaking. Suitable test methods and service life models for specification and assessment of concrete durability parameters were identified and will be presented in this report.

This conference represents the final event of the Technical Committee. It aims at bringing together experts from around the world, including researchers, practitioners, and infrastructure managers. It is anticipated that ongoing discussions and knowledge exchange will aid in developing guidelines for the application of suitable performance approaches for design, specification and quality control of concrete durability. These proceedings contain more than 70 papers on the general themes of concrete durability testing and modelling, concrete service life design, performance approaches for concrete durability, and modern concrete technology for improved durability performance.

All papers submitted for this RILEM International Workshop on Performance-Based Specification and Control of Concrete Durability were subjected to a full process of peer review, and the Proceedings contain only those papers that were accepted following this process. The review of manuscripts was undertaken by members of the International Scientific Advisory Board and other identified leading experts, acting independently on one or more assigned manuscripts. This invaluable assistance, which has greatly enhanced the quality of the Proceedings, is gratefully acknowledged.

Special acknowledgements are due to the following organisations for their support in the organisation of the workshop:
- Faculty of Civil Engineering, University of Zagreb
- Spegra Inženjering d.o.o.
- Proceq SA
- Nexe Beton d.o.o. Našice
- Journal of the Croatian Association of Civil Engineers Građevinar

Finally, the editors wish to thank the authors for their efforts at producing and delivering papers of high standard. We are sure that the Proceedings will be a valued reference for many working in this important field and that they will form a suitable base for discussion and provide suggestions for future development and research.

D. Bjegovic (University of Zagreb, Croatia)
H. Beushausen (University of Cape Town, South Africa)
M. Serdar (University of Zagreb, Croatia)
Editors

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