Inhaltszusammenfassung

We present the industrial collaboration project "HaloLIBS" for the development of a highly-sensitive LIBS method to detect halogens in reinforced concrete. The diffusion of chloride from de-icing salt into the concrete can provoke a corrosion of the steel-reinforcement (pitting corrosion). If the chloride contamination exceeds a certain level, this can result in a reduced stability and hence to a drastically shortened lifetime of infrastructure buildings like bridges or parking decks. Spatia...We present the industrial collaboration project "HaloLIBS" for the development of a highly-sensitive LIBS method to detect halogens in reinforced concrete. The diffusion of chloride from de-icing salt into the concrete can provoke a corrosion of the steel-reinforcement (pitting corrosion). If the chloride contamination exceeds a certain level, this can result in a reduced stability and hence to a drastically shortened lifetime of infrastructure buildings like bridges or parking decks. Spatially resolved techniques to quantitatively determine the local chloride concentration are required to estimate the demand of restoration. The conventional wet-chemical analysis is precise but cost- and time-consuming. Moreover, it cannot reveal chloride diffusion profiles alongside the concrete drilling core. The detection of atomic chlorine is a challenging task that needs sophisticated LIBS setups and measurements under helium atmosphere [1,2]. With timeresolved LIBS as an alternative method, we monitor the strong molecular emission of calcium chloride radicals (CaCl) formed during the plasma-cooling phase [3]. This can be performed without any sample preparation in ambient air. The quantification of the local distribution of halogens is deduced by multivariate statistics of the molecular spectral information. The Federal Institute for Materials Research and Testing (BAM) is responsible for the development of multiphase reference standards for quantification of halogens. The University of Applied Sciences Koblenz is developing the experimental LIBS setup for time- and space-resolved measurements and is simulating the radical formation process in the plasma-cooling phase to develop an appropriate quantitative analysis algorithm incorporating environmental parameters. SECOPTA analytics GmbH as the industrial partner is responsible for the development of a time-resolving polychromator to detect atomic and molecular emission. For the automated data evaluation, different chemometric methods for microcontrollers will be developed.» weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
Optik, Quantenoptik und Physik der Atome, Moleküle und Plasmen

DDC Sachgruppe:
Physik