The basis for the measurement system is formed by an electrically conductive material, which is integrated into a fabric. This hybrid fabric is incorporated into the asphalt base layer. The resistance of the sensor material changes due to its structural damage and consequently serves as a characteristic value for its time of failure. The damage processes caused by the loads in the asphalt affect the asphalt and, simultaneously, the integrated sensor fabric. It is therefore possible to infer the time of failure of the asphalt section from the fatigue state of the conductive material. Data on the actual internal condition of the base layer are provided, which, in the long term, can replace the previous drilling tests.
The transmission and storage of the data is also being examined as well as the secure data transport - from the road via various interfaces all the way through to the software and the companies carrying out the work. The processing and evaluation of the measurement results is performed through adaptation of a suitable software. For the interpretation of future measurements, the relationship between resistance change and degradation of the road is illustrated.
The carrier fabric, into which the sensor technology is integrated, is completely bio-based. The fabric development and production is being carried out at the Fraunhofer WKI in close cooperation with the Fraunhofer IFAM. At the Magdeburg-Stendal University of Applied Sciences, the measurement system is incorporated into asphalt test specimens and subjected to mechanical stress. In parallel, researchers at the Fraunhofer IFAM analyze the sensor technology and collect the data. The transport as well as the further processing of the data by means of suitable software are investigated and implemented primarily at the Hochschule Hannover, University of Applied Sciences and Arts.
In order to demonstrate and ensure the practical feasibility, a road-construction company is directly involved in the investigations and is supporting the research institutions in their efforts to define the locally applicable framework conditions.