With the aim of reducing life cycle costs and dead weight, there are various concepts for replacing bridge pavements and sealants with high‐performance concrete. The corrosion resistance of textile reinforcements allows the realization of thin reinforcement layers that fulfill this objective. However, the textile‐reinforced concrete used as a road surface must meet the particular requirements relating to frost resistance and, specifically, scaling. An investigation on an existing structure indicated the influence of textile reinforcements on frost resistance. Therefore, the present investigations focus on the frost scaling of different combinations of a carbon reinforcement and fine‐grained concrete. For this purpose, a multistage research design is used. First, the influence of the reinforcement and the concrete mix on the capillary porosity is investigated. The capillary porosity of concrete is directly related to its resistance to freeze–thaw scaling. This resistance is examined using the slab‐test method. Finally, the influence of the frost exposure on the pull‐off strength, which is crucial for the strengthening of structures, is determined.
Monitoring and surveillance of buildings, especially in critical infrastructure is crucial to increase the lifetime of such structures. This is due to fact, that buildings from reinforced concrete, like bridges or road tunnels are prone to corrosion due to their exposition to the elements. For this task, wireless sensor nodes can be employed in structural health monitoring. In the last few years passive RFID sensors have been proposed to gather data from inside concrete structures. However, designing antennas which are operational inside concrete to transmit data from the sensor node to the outside world is extremely challenging, due to the fact that the performance of antennas is extremely depended on their surrounding material. In this work, the fully automatized design of an antenna for the UHF band in concrete with varying electrical properties is demonstrated. Using a novel multi objective optimization method, the antennas are operational over a wide range of dielectric properties of the surrounding materials. In contrast to conventional approaches, no air spacers or boxes are needed around the antenna. The antenna parameters have been carefully obtained during the curing and drying process, in an outdoor like environment with 65 % relative humidity. After 157 days of drying, a reflection coefficient of −13 dB and an antenna gain of −8.4 dBi is achieved, at a water content of the concrete of 4.2 % by mass.
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