Indicators for the durability and service life of concrete structures

The identification of cost efficient maintenance strategies for concrete structures usually takes basis in condition assessments achieved through inspections, tests and monitoring. It is well recognized that such condition assessments are subject to significant uncertainties and in general at best provide indications rather than observations about the condition of the structure. This work proposes a probabilistic framework for the quantification of inspection results for concrete
structures in regard to their actual condition, the predicted future degradation, the estimated remaining service life and the expected service life costs of the structure. Within this context it is shown how condition indicators, based on non-destructive evaluation methods, can be formulated to enable quality control and inspection and maintenance planning. Furthermore it is investigated how the "strength" of the indicators not only depends on the inspection method but moreover may be significantly dependent on the age of the structure at the time of the inspection. The above are examined for localized degradation. Within the scope of this project is the development of models that may account for the spatial variability of the concrete properties and degradation processes. Hence the indicators established are to be further implemented together with the models of the spatial variability in order to establish risk indicators.

• Indicators for the durability and service life of concrete structures (ETH Research Database 389)