TY - CONF A1 - Bartholmai, Matthias A1 - Johann, Sergej A1 - Strangfeld, Christoph A2 - Chan, T. A2 - Mahini, S, T1 - Embedded wireless sensor systems for long-term SHM and corrosion detection in concrete components T2 - 8th International Conference on Structural Health Monitoring of Intelligent Infrastructure - Proceedings N2 - State-of-the-art communication standards like RFID and Bluetooth Low Energy enable the development of sensor systems which can be completely embedded into concrete components for long-term SHM and early damage detection. Objective of the project KonSens which is carried out at BAM is the development, implementation, and validation of sensors for measuring of Parameters relevant for corrosion, like moisture, pH value, and electrical conductivity, inside steel reinforced concrete components. The primarily addressed application is detection and evaluation of corrosion processes in concrete bridges. In contrast to cable connected sensors, embedded wireless sensors avoid any pathways for intrusion of moisture and chemicals, e.g., chlorides which could trigger corrosion activity. To allow for long-term, ideally life-time operation, the once embedded sensor systems must work highly energy efficient. One option are passive RFID sensor systems, which work without battery. The energy is transmitted to the system through the electromagnetic field, even to operate sensors. A crucial parameter is the transmission depth in concrete. First experiments with RFID sensors working at frequencies of 13.56 MHz (HF) and 868 MHz (UHF) embedded in concrete specimen resulted positive for transmission depths of up to 13 cm, which is quite promising, considering that corrosion would appear first at the top level of rebars. A second generation of passive RFID sensor systems has been implemented with improved antenna design. Current experiments using these systems focus on the Transmission characteristics in terms of transmission depths and the impact of concrete moisture. Low-energy humidity sensors are used and analysed regarding their capability for measuring the material moisture. Additionally, a relation between transmitted power to the embedded sensor and the moisture content of the concrete specimen caused by energy absorption can be presumed and is under systematic investigation. T2 - International Conference on Structural Health Monitoring of Intelligent Infrastructure 2017 CY - Brisbane, Australia DA - 05.12.2017 KW - RFID sensors KW - Structural health monitoring KW - Sensors in concrete KW - Smart structures PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/43492 AN - OPUS4-43492 SN - 978-1-925553-05-5 SP - 1 EP - 7 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany