PREFACE

Non-destructive evaluation and testing (NDT) is an important element for the assessment and maintenance of existing civil engineering structures. Non-destructive techniques are an essential means to detect internal damage and predict their extent or to provide information on the quality of the construction. Indeed evaluating the residual lifetime of existing structures requires information about the materials that they are made of.

Since the previous international symposiums on NDT in civil engineering, interest about such techniques has grown, induced by an increase of their accuracy, reliability and ease of use. Nevertheless, some issues still must be improved: their cost effectiveness through high rate acquisition, the knowledge of the links between non-destructive measurements and the determination of durability characteristics of the surveyed structures, for example.

The Confédération Française pour les Essais Non Destructifs (COFREND), the French association for Non Destructive Testing, was created in 1967 mainly for the management of the French NDT personnel certification system and the promotion of education and training in NDT. The importance of the Civil Engineering field within COFREND, completely marginal in the sixties and seventies, has become recently more prominent The Nantes region of France is second only to Paris in terms of education and research in Civil Engineering within France. This fact has led to the constitution of a National Competitive cluster (Pôle Génie Civil Eco-construction), which includes numerous research institutes, university organizations, and small and medium enterprises.

That is why the seventh International Non-Destructive Testing in Civil Engineering Symposium "NDTCE'09" will be held in Nantes. This symposium has been co-organized by the Laboratoire Central des Ponts et Chaussées (LCPC) (Division for Soil Mechanics and Site Survey - RMS), the Research Institute in Civil and Mechanical Engineering (UMR CNRS GeM) and COFREND. The conference will be held in the buildings of Ecole Centrale Nantes, a college that trains engineers for industry. The principal topics of the symposium deals are:

• Non-destructive testing for material and geometry characterization
• Recent developments in non-destructive methods
• Non-destructive testing for maintenance and reliability assessment

NDTCE'09 provides a high level technical and scientific environment in which professionals, scientists and academic staff can exchange ideas on new trends and emerging technologies on non-destructive testing for civil engineering. It brings together theory and practice, a better understanding of existing practice, and description and comparisons with new developments.

The conference will present more than 140 scientific papers, which have been reviewed by the NDTCE'09 Scientific Committee, coming from 26 countries. The papers will be presented during three and a half days in three parallel sessions. An exhibition of manufacturers and services related to NDT complete the conference.

The editors would like to thank all the individuals who helped in the organization of the symposium. In particular we thank the members of the Scientific Committee who devoted their time and energy to reviewing more than 210 abstracts and papers. Their efforts have helped to ensure the high quality of these proceedings. Thanks are also due to all the International Coordinators and co-sponsoring organisations for their efforts and commitment.

The editors would also like to thank their colleagues from GeM, especially Jean-Yves Hicher, Franck Schoefs and Abdelhafid Khelidj for the local organization in their own buildings, from COFREND, especially Cyril Kouzoubachian and Danielle Jeau for the financial management of this symposium, and from LCPC, Jean-Louis Chazelas and Géraldine Villain, for their continuous help during these past months.

Bernard Jacob, from LCPC, must be commended for the design and the management of our web site, Géraldine Villain, Vivien Bigourden for the preparation of these proceedings and Rolf Diederichs for the handling of the CD-ROM proceedings.

Finally, the editors would like to thank John Popovics, invited professor at LCPC during spring 2009, for his help with English in the final stages of the process.

Odile ABRAHAM

Xavier DEROBERT