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Determination of Chlorine and Carbon in Reinforced Concrete Structures by Double-Pulse LIBSтезисы доклада
- Авторы: Zorov N.B., Labutin T.A., Popov A.M., Zaytsev S.M., Belkov M.V., Kiris V.V., Raikov S.N.
- Сборник: Book of Abstracts EMSLIBS 2013 Bari (Italy) September 16-20, 2013
- Серия: Euro-Mediterranean Symposium on Laser Induced Breakdown Spectroscopy
- Том: 7
- Тезисы
- Год издания: 2013
- Место издания: University of Bari Bari, Italy
- Первая страница: 160
- Последняя страница: 160
- Аннотация: Recently LIBS is actively implemented for elemental analysis of building structures to discover destructive processes in them. The theoretical possibility of the LIBS characterization of a corrosion of building materials under atmospheric effect was demonstrated by Wilsch et al in 2005 [1]. The most corrosive hazardous elements (chlorine, sulfur, and carbon) for the degradation of building materials were determined by LIBS. However, the sensitivity of determination of nonmetals was insufficient for application as a standard analytical tool for chlorine and carbon determination in a concrete. The aim of this work was increasing the sensitivity of the LIBS determination of non-metals in the cement stone and reinforcement used in reinforced concrete by double-pulse excitation of plasma using both a laboratory setup and a transportable instrument Transportable LIBS instrument (~20 kg) consists of a diode-pumped, air-cooled Q-switched Nd:YAG laser with two resonators (1064 nm, 50 mJ per each pulse, pulse duration 8-12 ns, repetition rate up to 10 Hz); Czerny-Turner spectrograph (F=200 mm) equipped with a turret with four gratings and linear CCD detector. Laser is placed on a tripod with 3-D positioning. Laboratory setup is a typical gated LIBS system with various combination of harmonics of Nd:YAG laser. The combinations of harmonics of Nd:YAG laser (532+540, 532+355 and 540+266 nm) were used for analysis of cement stone and combination of 1064+1064 nm for analysis of the corroded reinforcement. To achieve maximal sensitivity of non-metal determination the spatiotemporal evolution of laser plasma was studied using different laser wavelengths. It is possible to optimize the time parameters for recording the analytical signal and the radiation focusing condition on the sample surface. The best results were observed when using the collinear scheme of the double-pulse excitation. Delay between laser pulses providing the maximal analytical signal enhancement for each element was determined. The detection limits, calculated by the 3s-criterion, were equal to 400 ppm for carbon and 50 ppm for chlorine. The achieved detection limits allow us to estimate the fatigue extend of reinforced concretes. [1] Wilsch G., Weritz F., Schaurich D., Wiggenhauser H., Construction and Building Materials. (2005) Vol.19 p.724-730
- Добавил в систему: Лабутин Тимур Александрович