scholarly journals Quantification of Chlorides and Sulphates on Concrete Surfaces Using Portable X-ray Fluorescence. Optimization of the Measurement Method Using Monte Carlo Simulation

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7892
Author(s):  
Servando Chinchón-Payá ◽  
Julio E. Torres Martín ◽  
Antonio Silva Toledo ◽  
Javier Sánchez Montero

A correct assessment of the pathologies that can affect a reinforced concrete structure is required in order to define the repair procedure. This work addresses the challenge of quantifying chlorides and sulphates directly on the surface of concrete. The quantification was carried out by means of X-ray fluorescence analysis on the surface of concrete specimens at different points with portable equipment. Concrete prisms were made with different amounts of NaCl and Na2SO4. To avoid the influence of coarse aggregate, a qualitative estimate of the amount of coarse aggregate analyzed has been made, although the results show that there is no significant influence. Monte Carlo simulations were carried out in order to establish the necessary number of random analyses of the mean value to be within an acceptable range of error. In the case of quantifying sulphates, it is necessary to carry out six random analyses on the surface, and eight measurements in the case of quantifying chlorides; in this way, it is ensured that errors are below 10% in 95% of the cases. The results of the study highlight that a portable XRF device can be used in situ to obtain concentrations of chlorides and sulphates of a concrete surface with good accuracy. There is no need to take samples and bring them to a laboratory, allowing lower overall costs in inspection and reparation works.

2009 ◽  
Vol 54 (5) ◽  
pp. 420-423 ◽  
Author(s):  
Tsunenori Matsunaga ◽  
Hidetaka Ishizaki ◽  
Shuji Tanabe ◽  
Yoshihiko Hayashi

2019 ◽  
Vol 11 ◽  
Author(s):  
A. G. Karydas ◽  
T. Pantazis ◽  
C. Doumas ◽  
A. Vlachopoulos ◽  
P. Nomikos ◽  
...  

In-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area was performed using a novel X-ray instrumentation, composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses in Akrotiri was to explore the potential of the technique to provide answers to a wide range of archaeometric questions regarding the bulk composition of metal alloys, especially of gold, the characterization of corrosion products in bronze artifacts, identification of inorganic elements which are fingerprints of the minerals used in wall-painting pigments, and of the painting materials and techniques used for the decoration of clay vase surfaces. Among the analysed artifacts are a unique gold ibex, a bronze dagger and blade, various pigments from the wall paintings of room 3 in Xeste 3, decoration pigments from rosettes of faience, a bichrome jug, and other clay vases. The results of the in-situ XRF survey, primarily those of the bulk composition and soldering technology of the gold ibex, are discussed and compared with literature.


2011 ◽  
Vol 178-179 ◽  
pp. 353-359 ◽  
Author(s):  
Johannes Will ◽  
Alexander Gröschel ◽  
Christoph Bergmann ◽  
Andreas Magerl

The measurement of Pendellösungs oscillations was used to observe the time dependent nucleation of oxygen in a Czochralski grown single crystal at 750°C. It is shown, that the theoretical approach of the statistical dynamical theory describes the data well. Within the framework of this theory it is possible to determine the static Debye-Waller-factor as a function of the annealing time by evaluating the mean value of the Bragg intensity and the period length. The temperature influence on the Pendellösungs distance was corrected for by measurement of a Float-zone sample at the same temperature.


Author(s):  
R. E. Ogilvie ◽  
S. H. Moll ◽  
M. A. Schippert

An X-ray spectrometer has been developed to extend the analytical capability of the Philips EM-200/EM-300 Electron Microscopes to studies of sample chemistry. It attaches directly to the objective aperture port of the rotating/tilting specimen stage.Shown in Figure 1, the spectrometer is a high resolution instrument, employing a mica crystal which is continuously curved to fulfill the X-ray focusing conditions over the entire angular range. Equipped with a flow proportional counter, it is capable of analyzing characteristic X-ray lines of any element from Na through U. With the rotating/tilting specimen stage and a replacement aperture installed in the microscope, the spectrometer may be attached to or removed from the instrument in less than five minutes. It may also be left in situ during normal use of the microscope.Supplementing the present ability of the electron microscope to investigate morphology and crystal structure (by electron diffraction), the spectrometer allows the simultaneous determination of chemical composition by microprobe X-ray fluorescence analysis of areas approximately one micron in diameter.


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