The book presents the work of the RILEM Technical Committee 249-ISC. Addressing the effective application of new recommendations for non-destructive in situ strength assessment of concrete, it provides information about the different steps of the investigation and processing of test results, until the delivery of strength estimates, and includes tables giving the minimum required number of cores in a variety of situations as well as several examples of how the recommendations can be used in practice. The book explores a topic which is of major importance, i.e. the assessment of concrete compressive strength in existing structures. This property (both mean and standard deviation) is a key input in many cases, such as the reinforcement of structures, the safety checking, the extension of service life.
As the new RILEM recommendations imply a deep revision (and improvement) of field practice, the book is intended for managers of structures, structural engineers and specialists of NDT that have to answer these issues. More widely, it will benefit engineers and students who are interested in NDT and in the safety analysis of structures.

Denys Breysse is professor at the Department of Civil and Environmental Engineering at the Institute of Mechanics and Engineering (I2M) within the Bordeaux University, France. His research interests focus on: non-destructive testing and the use of data provided by NDT for reassessing the material condition and the structural safety; risk management in Civil Engineering structures and projects; heterogeneities at various scales in building materials and their consequences on safety; modelling of stochastic processes for civil engineering materials and structures.

He founded the French association for RIsk MAnagement in Civil Engineering (@MRGenCi) in 2003 and was its first President. He was Chair of the French Association for Civil Engineering Academics (AUGC), chairman of the RILEM TC-INR 207 on combination of NDT in reinforced concrete of the RILEM TC-ISC 249.

In-situ strength assessment of concrete: detailed guidelines.- How to identify the recommended number of cores?.- Evaluation of concrete strength by combined NDT techniques: practice, possibilities and Recommendations.- Identification of test regions and choice of conversion models.- Identification and processing of outliers.- How investigators can assess concrete strength with on-site non-destructive tests and lessons to draw from a benchmark.- How investigators can answer more complex questions about assessing concrete strength and lessons to draw from a benchmark.- Illustration of the proposed methodology based on synthetic data.- Illustration of the proposed methodology based on a real case-study.- Statistics.- Model identification and calibration.- For those who want to go further.