Smart Concrete
In the sector of structural engineering, the preservation and management of prestressed reinforced concrete civil infrastructures are fundamental. Nevertheless, when implemented, the project, building and testing work at present do not include technical measures which may verify the development of safety factors throughout the lifetime of the building, nor the level of structural reliability in case of exceptional occurences which may concern the building. In the last few years sensitivity has increased in sectors such as automated and permanent structural monitoring, in particular as far as reinforced concrete buildings are concerned. This, enhanced by constant technological progress, has developed above all thanks to the growing awareness on behalf of of engineers that even in civil engineering it may be possible to introduce and develop the concept of smart structure, as already seen in sectors such as mechanics and aviation, where the most strategical structural elements embody devices through which it may be possible to measure directly the staus of efficiency and reliability. At present, as far as reinforced concrete and prestressed reinforced concrete buildings are concerned, structures such as bridges, viaducts, stadiums, tunnels, skyscrapers etc are monitored by external sensors (accelerometers, anemometers, …) which provide information about the structural reactions but not the intrinsic tension status. This is due to the fact that the solutions we have, e.g. the use of optical fiber sensors inserted in the concrete of particular sections of some tunnels, are extremely complex and costly and for this reason they are not widely used.
The solutions of Structural Health Monitoring (SHM) (system and service), will help to keep concrete structures under control. Creating a network of sensors designed for the purpose and kept in the frame of the building material, it will be possible to control different paramenters, critical for structural safety and useful for an adequate planning of maintenance interventions. Furthermore the above-mentioned sensors may be installed afterwards in reinforced or prestressed concrete structures; obviously in such a case they would be able to detect any tension which may arise after their installation such as, in general, variable actions and sometimes a share of permanent actions. The application of sensors is particularly relevant in monitoring the actual deterioration of existing structures in comparison with the expected degradation, in particular when it is possible to apply priority intervention criteria on several deteriorated structures, belonging to the same infrastructure. In particular,the tension in the reinforced concrete elements (which represent the foundations and the supporting structure of buildings, bridges, viaducts etc) will be monitored by specific sensors, interconnected and accessible through RFID players, allocated inside the building material and therefore within the structure.
The complexity of the project is a real challenge since there are no reliable systems worldwide able to perform tensor measures within structural elements. If the project were to be successful, this would represent a radical innovation in monitoring structures; in fact to the present day there are no solutions at all to esteem the tensor status of structures from “the inside” with low-cost equipment that do not require highly-qualified staff to carry out measuring.
The results from the proposal and the Structure Health Monitoring (SHM) system/service affect the safety of our infrastructures and life environments, and support, in the Smart Cities sector, the development of more sustainable “Architectures”, as far as safety and health are concerned, and smarter in terms of interconnection and interactive capacity, thanks to the use of ICT technologies within the building material and an open and interoperable SW platform which may interact with the applications from the perspective of the “Zero Impact Building” principle.