TY - CONF A1 - Helmerich, Rosemarie A1 - Moldenhauer, Laura A1 - Voigt, Gerrit A1 - Köppe, E. T1 - Considerations for identification of moisture in building materials using Bluetooth (R) T2 - Maintenance, safety, risk, management and life-cycle performance of bridges N2 - The vulnerability of low-quality concrete of some bridges to ageing and deterioration while they are exposed to environmental conditions during their service life, influence of growing population and climate changes, is a well-known effect and requires survey. For survey, the development of a low cost, cost-efficient sensor network to be embedded for continuous or attached to the surface for periodic monitoring is essential. Changing ground water conditions, flood or even leakage in fresh or disposal of waste water can lead to in-creased moisture content in building materials and structural elements as walls or floors. Moisture allows the transport of other adverse chemicals that might reduce the durability of structures. The paper presents a feasibility study about the capability of microwave modules as bluetooth® or ZigBee with frequency range at 2,4 GHz to create advanced Wireless Sensor Networks (WSN) for estimation and visualization of moisture distribution in infrastructure assets. It was found that the value of the received signal strength indication (RSSI) depends on the moisture content and can be the basis for the moisture distribution inside a massive structure. The microwave modules may be used to compose networks outside and inside of building materials or structural elements. The higher the number of connections between BLE modules, the more precise and the more distant information can be obtained from the network. Mesh networking was applied to increase the quantitative information. T2 - 9th International Conference on Bridge Maintenance, Safety and Management (IABMAS) CY - Melbourne, Australia DA - 09.07.2018 KW - Structural Health Monitoring KW - Moisture KW - Bluetooth PY - 2018 SN - 978-1-315-18939-0 SN - 978-1-138-73045-8 SP - 2752 EP - 2759 AN - OPUS4-50340 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moldenhauer, Laura A1 - Helmerich, Rosemarie A1 - Köppe, E. A1 - Wittmann, J. ED - Cosmi, F. T1 - Experimental modeling approach for determining the moisture damping exponent of a Bluetooth Low Energy signal in moist building material T2 - 34th Danube Adria Symposium N2 - The presented development of a damping model is a research component of an experimental feasibility study about moisture in building materials measured with Bluetooth® Low Energy (BLE) signals. This study may be part of a structural health monitoring aiming on early damage detection in the built infrastructure and is increasingly focusing on wireless sensor Network technology. It is investigated, how the Received Signal Strength Indicator (RSSI) of a BLE signal, transmitted from the BLE-module embedded in building materials with changing moisture content is damped. The BLE-module communicates with a mobile Smart Device as tablet or mobile phone via 2.45 GHz-ISMfrequency band where water dipoles start to oscillate. If the BLE-signal transfers through a moist material, the moisture Content influences the RSS-Indicator. The damping model demonstrates this damping effect on RSSI by the abstraction of the reality observed in a real system. T2 - 34th Danube Adria Symposium CY - Trieste, Italy DA - 19.09.2017 KW - Moisture damping coefficient, KW - Buliding materials KW - Bluetooth Low Energy KW - RSSI KW - Experimental approach PY - 2017 SN - 978-88-8303-863-1 DO - https://doi.org/https://www.openstarts.units.it/handle/10077/14834 SP - 141 EP - 142 CY - Trieste, Italy AN - OPUS4-44528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moldenhauer, Laura A1 - Helmerich, Rosemarie A1 - Köppe, Enrico A1 - Haamkens, Frank A1 - Wittmann, Jochen ED - Aulova, Alexandra ED - Rogelj Ritonja, Alenka ED - Emri, Igor T1 - Experimental feasibility study about moisture in building materials measured with bluetooth T2 - The 33rd Danubia Adria Symposium on Advances in experimental mechanics N2 - Structural health monitoring contributes to early damage detection in the built infrastructure. During the last two decades, the sensor networks transferred from wired to wireless sensor networks. Several methods exist to measure moisture in building materials. Most of the introduced commercial humidity measurement methods as provide information about the local or near surface moisture. A feasibility study is presented to demonstrate, how the Received Signal Strength Indicator (RSSI) of a BlueTooth® Low Energy (BLE) signal, transmitted from the BLE-module embedded in building materials with changing moisture content. The BLE-module communicates with a mobile Smart Device as tablet or mobile phone. The RSSI indicates to what extend the received signal strength is changed due to moisture, while the transmitted signal strength remains constant. T2 - The 33rd Danubia Adria Symposium on Advances in experimental mechanics CY - Portoroz, Slovenia DA - 20.09.2016 KW - Bluetooth KW - Moisture KW - Measurement KW - Water dipoles KW - RSSI PY - 2016 SN - 978-961-94081-0-0 SP - 60 EP - 61 PB - SSEM--Slovene Society of Experimental Mechanics CY - Ljubljana, Slovenia AN - OPUS4-38086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -