Existing concrete structures: Life management, testing and structural health monitoring

Past and recent events, for instance the collapse of the Morandi Bridge and several other collapses of engineering structures, demonstrate the increasing importance of a reliable condition assessment of structures based on testing and monitoring. Especially this applies for new and existing concrete structures where the intervention planning (e.g., maintenance, repair, rehabilitation, replacement) has to comply with special performance and cost requirements associated with environmental conditions and social needs. Despite the many years of research and operation, there is still a strong demand for the development and efficient implementation of novel monitoring and assessment techniques for concrete structures ensuring societal safety formats. On the other hand, as we can see from the technical developments, novel monitoring and assessment techniques also enable new perspectives regarding intervention and maintenance strategies and in consequence cost and life cycle optimization concepts. Thus, one objective of this issue is to highlight the recent developments in science and practice in this important field and to formulate the next necessary steps in the area of assessment and monitoring. This special issue also supports the goals of the fib Commission 3, focused on existing concrete structures, and the implementation of innovative life management, testing and structural health monitoring concepts in the upcoming fib Model Code 2020. Specifically, the interesting content of this special issue resulted from the work of the fib task group TG3.3 “Assessment/evaluation and decision-making procedures for the through-life management of existing concrete structures” and of the fib action group AG9 “Testing and monitoring of existing structures.” The contributions presented in this issue deal with state-of-the-art as well as emerging applications related to the key aspects of life management, testing, and the structural health monitoring field. Major aspects of life cycle engineering, assessment procedures, and monitoring are addressed, including aging of structures, deterioration modeling, durable materials, structure–environment interaction, failure analysis and risk prevention, lifetime structural optimization, long-term performance analysis, service life prediction, time-variant reliability, uncertainty modeling, damage identification, field testing, health monitoring, inspection and evaluation, maintenance strategies, and decision-making processes. The aim of the editors is to provide a valuable source for anyone interested in life management, testing, and structural health monitoring concepts of civil infrastructure systems, including students, researchers, and practitioners from all areas of engineering and industry. On behalf of the chairs of the fib commission COM3, fib task group TG3.3, fib action group AG9, and the University of Natural Resources and Life Sciences, the editors wish to wholeheartedly thank all contributing authors and colleagues actively involved in the organization and production of this special issue and several fib members for their efforts in the advising and reviewing process. The editors are particularly grateful to Luc Taerwe and David Fernandez-Ordoñez for their time and efforts dedicated in making this issue a success. We wish you some exciting hours with this selection of papers that we do hope you will find informative and interesting as we did.