Industrial design of instrumented PRC elements for the condition monitoring of civil infrastructure

Recognizing the growing importance of new technologies in the life-cycle management of civil infrastructure, the University of Trente is promoting a research effort aimed at developing a novel construction system that will allow real-time condition monitoring of bridge structures. The general concept is to build new bridges using smart structural elements, i.e. precast RC elements embedding a sensing system and capable of self-diagnosis. Sensors are conceived as an integral part of the prefabricated element, influencing its design criteria, performance and detailing. A first step of the research was accomplished in 2004 with the construction and testing of reduced-scale prototypes of smart elements. The second phase aims at demonstrating the industrial feasibility of the series production of prefabricated elements embedding FOS technology as well as their in-field reliability. In detail, the program includes the production of two 28m-long prestressed RC box-beam elements. One of these will be used in a single span road bridge, while the other will be extensively tested in the laboratory, in order to record and identify the response signature associated with recurrent deterioration scenarios. The general paradigm of the design is to conceive the sensing system in two separate parts, embeddable and external. The embeddable part is to be permanently installed in the element, and therefore must have high durability and robustness, while the external sensing system can be replaced during routine maintenance work or as necessary in the case of malfunction, or for technology upgrade.