Supervised lifetime extension of endangered concrete structures by health monitoring

State assessment results of conventional or advanced experimental investigations of existing concrete structures (e.g. using the 'EXTRA-'method) are absolutely valid at the time of testing, but usually not longer than a time of at most five to ten years after the testing date. Thereafter the assessment results will be more and more unsure because of progressing (often unknown) deterioration processes. At the latest at that time a repeated (but expensive) test procedure would be necessary. In the most of these cases (but of course also in many other situations) the concept of a supervised lifetime extension by monitoring of a small number of key- measurands would be the more safer and reasonable solution. Since two years the authors have a close cooperation with the aim to develop a remote monitoring system for fields of application like mentioned before. Based on experiences collected on different applications of such a system more general demands on an efficient system configuration could be derived. An overview on the main characteristics is systematized by matrix elements defined by the main demands flexibility, robustness and reliability as well as the main system components hardware, software and application management. Afterwards it will be shown exemplary (system structure, measurement modes, sensor selection criteria, data transmission, data management as well as optional features like solar energy supply or overload truck identification) how the remote monitoring system SMS 2001R is able to fulfill the demands discussed before and which further developments are under way respectively. Finally some experiences from the first presentation of a SMS 2001R in the United States will be added.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.