TY - CONF A1 - Strangfeld, Christoph A1 - Kruschwitz, Sabine A1 - Wöstmann, Jens A1 - Munsch, Sarah Mandy A1 - Hase, Felix T1 - Moisture in screed: a non-destructive multi-sensor approach N2 - Eight different screed types are tested including two different sample heights of 35 and 70 mm. The moisture of the four cement based and four sulphate based screeds are monitored during hydration and evaporation. All samples are stored in a climatic chamber at 23° C and 50 % relative humidity. Embedded sensors like temperature arrays, humidity sensor arrays, and multi-ring electrodes are embedded in the samples to yield a detailed moisture evolution with high depth resolution. Furthermore, nuclear magnetic resonance is used to quantify the water content at different depths. This multi-sensor approach allows a comprehensive monitoring of the moisture and its gradient in the different screed samples. This yields a deeper insight into the hydration, moisture convection, and diffusion processes. T2 - EWSHM 2016 CY - Bilbao, Spain DA - 05.07.2016 KW - Moisture KW - Screed KW - Embedded sensors KW - Corresponding relative humidity KW - NMR PY - 2016 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-36840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Johann, Sergej A1 - Müller, Maximilian A1 - Bartholmai, Matthias T1 - Moisture Measurements with RFID based Sensors in Screed and Concrete N2 - To quantify the moisture in concrete, RFID based humidity sensors are embedded. Passive high frequency, ultra-high frequency RFID tags as well as active Bluetooth sensors are tested. After concreting, all sensors measure the corresponding relative humidity to monitor the concrete moisture. Two case studies are performed, embedding in an existing construction, i.e. the duraBASt test bridge, and embedding in cement based mortar in the laboratory. As basis for robust and long-life sensors in alkaline concrete, different casing materials are tested. Furthermore, signal strength measurements and their sensitivity to different moisture levels are performed. T2 - EWSHM 2016 CY - Bilbao, Spain DA - 05.07.2016 KW - Moisture measurements KW - RFID based sensors KW - DuraBASt KW - Humidity sensors KW - Long-life sensor casing PY - 2016 AN - OPUS4-36834 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Fakhouri, Abdalla A1 - Wiggenhauser, Herbert T1 - Intelligent bridge: the durabasttest bridge equipped with RFID-based sensors N2 - The duraBASt area at the highway intersection “Köln-Ost” is a large test field for road testing. It includes the duraBASt test bridge which is ca. 66 m long and 14.25m broad. This bridge is part of the “road in the 21st century” project and is equipped with several sensors for structural health monitoring. This feasibility study is realised to construct intelligent bridges in the future. Quantities like temperature, strain, moisture, corrosion, etc. are measured by embedded sensors. In the presented work, the focus lays on passive RFID-based sensors. The communication and energy supply is realised by a mobile transmitter through the concrete cover. Hence, no cables or batteries are required. The sensors are design to withstand in the alkaline environment in concrete. Thus, moisture and corrosion are detectable for several decades. T2 - Structural Materials Technology 2016 CY - Portland, ME, USA DA - 29.08.2016 KW - RFID based sensors KW - SHM in civil engineering PY - 2016 AN - OPUS4-37466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -