Using of the Ultrasonic Method for Alkali-Silica Reaction Detection in the Cement Mortar

2021 ◽  
Vol 321 ◽  
pp. 29-35
Author(s):  
Dimitrii Gusak ◽  
Jiří Brožovský ◽  
Rudolf Hela
Keyword(s):  
Internal Structure ◽  
Propagation Velocity ◽  
Cement Mortar ◽  
Ultrasonic Method ◽  
Alkali Silica Reaction ◽  
Extensive Investigation ◽  
Internal Corrosion ◽  
Impulse Propagation ◽  
Structure Changes

The alkali–silica reaction (ASR) causes internal corrosion of concrete. The aim of this work is to verify the possibility of ultrasonic method in detection of concrete internal structure changes, which were initiated by the alkali-silica reaction. For this purpose, we prepared samples that contained aggregates of two types, namely one with 98% of SiO2 content and one with a greywacke. The dependence of ultrasonic impulse propagation velocity on the changes in the structure of mortars containing aggregates from these rocks was researched. The results of this work are not unambiguous yet and therefore it is necessary to carry out more extensive investigation with using of other methods that will allow to examine changes in the internal structure of composites more detailed.

Methodology for assessing the uncertainty of measurements of mechanical stresses by the ultrasonic method with the help of an optical-acoustic separate-combined transducer

2021 ◽  
Vol 2127 (1) ◽  
pp. 012036
Author(s):  
A V Fedorov ◽  
V A Bychenok ◽  
I V Berkutov ◽  
I E Alifanova ◽  
A E Khoshev
Keyword(s):  
Ultrasonic Wave ◽  
Propagation Velocity ◽  
Ultrasonic Method ◽  
Mechanical Stresses ◽  
Acoustic Transducer ◽  
Head Waves ◽  
Uncertainty Of Measurements ◽  
Coupling Parameters ◽  
Object Of Control ◽  
Thermoacoustic Coupling

Abstract The work is devoted to the ultrasonic method of controlling mechanical stresses using ultrasonic head waves. The factors that contribute to the result of measurements of mechanical stresses include: the propagation velocity of the head ultrasonic wave, the temperature of the environment and the object of control, the coefficients of acoustoelastic and thermoacoustic coupling, parameters of the optical-acoustic transducer. The contribution of each of these factors to the results of measurements of mechanical stresses is assessed. A technique for assessing the uncertainty of measurements of mechanical stresses by the ultrasonic method using head waves has been developed.

Effect of Nanoclay on the Expansive Potential of Cement Mortar due to Alkali-Silica Reaction

2015 ◽  
Vol 112 (6) ◽  
Author(s):  
Mohammad R. Irshidat ◽  
Mohammed H. Al-Saleh ◽  
Sura Sanad
Keyword(s):  
Cement Mortar ◽  
Alkali Silica Reaction

scholarly journals Effect of Moisture Distribution on Velocity and Waveform of Ultrasonic-Wave Propagation in Mortar

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 790
Author(s):  
Shinichiro Okazaki ◽  
Hiroma Iwase ◽  
Hiroyuki Nakagawa ◽  
Hidenori Yoshida ◽  
Ryosuke Hinei
Keyword(s):  
Wave Propagation ◽  
Surface Layer ◽  
Moisture Content ◽  
Ultrasonic Wave ◽  
Propagation Velocity ◽  
Analytical Study ◽  
Quality Evaluation ◽  
Ultrasonic Method ◽  
Moisture Distribution ◽  
Ultrasonic Wave Propagation

Considering that the ultrasonic method is applied for the quality evaluation of concrete, this study experimentally and numerically investigates the effect of inhomogeneity caused by changes in the moisture content of concrete on ultrasonic wave propagation. The experimental results demonstrate that the propagation velocity and amplitude of the ultrasonic wave vary for different moisture content distributions in the specimens. In the analytical study, the characteristics obtained experimentally are reproduced by modeling a system in which the moisture content varies between the surface layer and interior of concrete.

The Effect of Modifications on Humidity Parameters of Cement Mortar

2016 ◽  
Vol 865 ◽  
pp. 178-182
Author(s):  
Maria Wesołowska ◽  
Anna Kaczmarek
Keyword(s):  
Moisture Transport ◽  
Mesoporous Material ◽  
Cement Mortar ◽  
Mercury Porosimetry ◽  
Capillary Rise ◽  
Complex Structure ◽  
Structure Changes ◽  
Cement Mortars ◽  
Study Results ◽  
The Impact

Current wall constructions utilize cement mortars, the properties of which have been modified with introducing lime or plasticizers. The complex structure of these mortars as well as their very large inner area results in large differences in capillary moisture transport. Macroscopic studies do not allow to accurately predict the mortar behaviour in contact with water. Capillary rise as well as drying and freezing of water are dependent on the size and the layout of pores. The biggest adsorption capacity is featured by micropores. Moisture transport takes place in mesoporous material, and moisture adsorption takes place on the surface of such materials. Macropores mainly act as a transport medium and carry moisture to mesoporous material and micropores. In terms of mesoporous material and macropores mercury porosimetry is more suitable. Mortar structure plays an important role in the moisture transport. Mortar additives, that have been introduced in the form of lime and plasticizers, modify the distribution and size of pores. Porosimetric study results concerning selected mortars have been presented in this article. The structure changes resulting from the introduction additives to mortars have been analyzed and the impact on humidity of such mortars has been defined.

scholarly journals Non-Destructive Assessment of Masonry Pillars using Ultrasonic Tomography

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2543 ◽  
Author(s):  
Monika Zielińska ◽  
Magdalena Rucka
Keyword(s):  
Computed Tomography ◽  
Velocity Distribution ◽  
Internal Structure ◽  
Cement Mortar ◽  
Tomographic Imaging ◽  
Stress Waves ◽  
Ultrasonic Tomography ◽  
Reinforcing Bar ◽  
Steel Bar ◽  
Non Destructive

In this paper, a condition assessment of masonry pillars is presented. Non-destructive tests were performed on an intact pillar as well as three pillars with internal inclusions in the form of a hole, a steel bar grouted by gypsum mortar, and a steel bar grouted by cement mortar. The inspection utilized ultrasonic stress waves and the reconstruction of the velocity distribution was performed by means of computed tomography. The results showed the possibilities of tomographic imaging in characterizing the internal structure of pillars. Particular attention was paid to the assessment of the adhesive connection between a steel reinforcing bar, embedded inside pillars, and the surrounding pillar body.

scholarly journals A mesonic analog of the deuteron

2014 ◽  
Vol 23 (12) ◽  
pp. 1450091 ◽  
Author(s):  
Richard R. Silbar ◽  
T. Goldman
Keyword(s):  
Binding Energy ◽  
Internal Structure ◽  
B Meson ◽  
D Meson ◽  
Bound State ◽  
Variational Calculation ◽  
State Structure ◽  
Structure Changes ◽  
Quark Structure ◽  
Hadronic System

Using the LAMP model for nuclear quark structure, we calculate the binding energy and quark structure of a B meson merging with a D meson. Our variational calculation shows that a molecular, deuteron-like state structure changes rather abruptly, as the separation between the two mesons decreases, and at a separation of about 0.14 fm, the hadronic system transforms into a four-quark bound state, although one maintaining an internal structure rather than that of a four-quark "bag." Unlike the deuteron, pion exchange does not provide any contribution to the ≈ 150 MeV binding.

Spectral reflectance and leaf internal structure changes of barley plants due to phytoextraction of zinc and cadmium

2007 ◽  
Vol 28 (5) ◽  
pp. 1041-1054 ◽  
Author(s):  
B. B. Maruthi Sridhar ◽  
F. X. Han ◽  
S. V. Diehl ◽  
D. L. Monts ◽  
Y. Su
Keyword(s):  
Internal Structure ◽  
Spectral Reflectance ◽  
Structure Changes

scholarly journals Polymer action on alkali–silica reaction in cement mortar

2013 ◽  
Vol 44 ◽  
pp. 97-105 ◽  
Author(s):  
João Feiteira ◽  
Maria S. Ribeiro
Keyword(s):  
Cement Mortar ◽  
Alkali Silica Reaction
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