Evaluation of Degradation of Concrete Exposed to High Temperature by Means of Ultrasonic Pulse Method

2013 ◽  
Vol 284-287 ◽  
pp. 1315-1319 ◽  
Author(s):  
Jiří Brožovský ◽  
Lenka Bodnárová ◽  
Rudolf Hela ◽  
Rostislav Drochytka ◽  
Vlastimil Hela

Ultrasonic pulse method is a non-destructive testing method used for testing materials. For concrete, it is used mostly for determination of dynamic elasticity modulus, compressive strength, homogeneity, to determine depth of cracks or as a supportive method for testing frost resistance. Applicability of using ultrasonic pulse method for evaluation of degradation of concrete exposed to high temperature was proved. This method is unambiguously utilizable for rationalization of experimental work focused on optimization of composition of concrete resistant to high temperatures. Ultrasonic pulse method can be also used for mapping the degree of degradation of concrete elements and structures, which can be measured by means of direct sounding. Appropriateness of the use of ultrasonic pulse method for evaluation of degradation of concrete exposed to high temperature was proved. This method is unambiguously applicable for rationalization of experimental work focused on optimization of composition of concrete resistant to high temperatures. Ultrasonic pulse method can be also used for mapping degree of degradation of concrete elements and structures, which can be measured by means of direct sounding.

2018 ◽  
Vol 15 ◽  
pp. 99-103 ◽  
Author(s):  
Iva Rozsypalová ◽  
Michal Vyhlídal ◽  
Richard Dvořák ◽  
Tomáš Majda ◽  
Libor Topolář ◽  
...  

In this paper, the attention is paid to the investigation of the influence of high temperature acting on specimens made from specially designed cement-based composite. The experimental programme was carried out on six sets of beam specimens with the dimensions of 20 × 40 × 200 mm. The specimens were loaded to a pre-set temperature of 100, 200, 400, 600, 800 and 1000 °C and then the temperature was kept for 60 minutes. When the temperature loading had been done, the specimens were left to cool down to the ambient temperature. After that, the ultrasonic pulse method was used to determine the degree of damage of temperature loaded specimens. The measured data obtained by this non-destructive method are in high correlation with values of informative compressive strength of the composite obtained after the temperature loading of specimens.


2016 ◽  
Vol 827 ◽  
pp. 324-327
Author(s):  
Pavel Reiterman ◽  
Ondřej Holčapek

Present paper is focused on the experimental assessment of three sandstones from different quarries. Mechanical testing was carried out besides water absorption test and determination of frost resistance what is the crucial material parameter for all types of porous rocks. Gradual deterioration due to action of frost was monitored using non-destructive testing – ultrasonic pulse method. Obtained results well describe failure mechanism of studied sandstones of different basic physical properties. It was conducted that main part of deterioration was performed at the beginning of the freeze-thaw cycling.


2018 ◽  
Vol 219 ◽  
pp. 03003
Author(s):  
Richard Dvořák ◽  
Zdeněk Chobola ◽  
Ivo Kusák

The paper is focused on non-destructive measurement of high temperature degraded concrete test specimens of three mixtures different by the use of coarse aggregate. Testing is done by ultrasonicpulse velocitymethod and Impact-Echo method. Non-destructive results are compared with destructive tests. Ultrasonic pulse velocity, dominant resonance frequency and acoustic impedance are discussed and compared with changes in density, cubic compressive strength, and tensile strength of concrete. The paper suggests possible assessment of degraded concrete by the change in acoustic impedance dependent on residual tensile strength.


Safety ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Tereza Komárková ◽  
Jaromír Láník ◽  
Anton Ondřej

Traffic barriers represent one of the basic road safety features. There are several types of traffic barriers based on the material from which they are made of and their location. Bridge structures are usually fitted with steel barriers. A steel barrier is, in fact, a relatively complex system linking individual steel elements, which, as a whole, has to meet the requirements given by normative regulations. In order for the steel barriers to fulfill their function and prevent the catastrophic consequences of traffic accidents, it is absolutely necessary to ensure their correct installation on the bridge structure. It seemed until recently that carrying out quality inspections of steel barriers installation, i.e., their anchoring into the concrete ledges, was a relatively complicated time- and money-consuming process, and that is why inspections of the correct anchoring installation in new or existing barriers were not carried out as standard. This paper thoroughly describes in detail the non-destructive ultrasonic pulse method, with which the anchoring of steel barriers on selected bridge structures is being checked. From the measurements and statistical evaluation of the results, it is apparent that carrying out inspections of the anchoring of these road safety features should be considered routine, and at the same time, the inspection of anchoring quality should be required by law in order to ensure the safety of road traffic.


2021 ◽  
Author(s):  
◽  
Matthew Thomson

<p>This thesis focuses on the application of high frequency ultrasound as a tool for performing non-destructive testing for pultruded fibre reinforced composite (FRC) rods. These composite rods are popular in the manufacturing, construction and electrical industries due to their chemical, electrical and strength properties. Such FRCs are manufactured on automated production lines that operate day and night. Non-destructive testing techniques are desired to quickly and accurately detectmanufacturing flaws such as coating thickness irregularities and surface cracks. Layers and cracks can present as large changes in acoustic impedance and will strongly reflect ultrasonic waves. Combined with their low cost, east of use and absense of potentially harmful radiation, ultrasound has proven popular worldwide for Non-Destructive Testing. Finite Element Analysis (FEA) was employed to investigate the propagation of ultrasonic waves through layers of material to simulate a thickness measurement and the ability of ultrasound to measure thicknesses was proven. Experimental work was conducted on two fibre reinforced composite samples with varying thickness coatings of plastic and paint. The thickness was measured accurately using immersion transducers at 50MHz and a resolution of 20μm was attained through the use of matched filtering techniques. Surface acoustic waves, particularly Rayleigh waves were investigated using FEA techniques so that the generation, scattering and detection of such waves was understood. This lead to the development of methods for detecting surface cracks in glass using Rayleigh waves and these methods were successfully used in experimental work. Wave propagation in fibre reinforced composites was modelled and experimentally investigated with the results confirming theoretical expectations. Finally a Rayleigh wave was launched onto a fibre reinforced composite sample however the amount of energy leakage into the water was so great, due to the acoustic impedance of water, the detection of the wave was prevented. The conclusion reached was that an immersion setup was not appropriate for launching a travelling Rayleigh wave.</p>


2011 ◽  
Vol 243-249 ◽  
pp. 165-169 ◽  
Author(s):  
Iqbal Khan Mohammad

Nondestructive testing (NDT) is a technique to determine the integrity of a material, component or structure. The commonly NDT methods used for the concrete are dynamic modulus of elasticity and ultrasonic pulse velocity. The dynamic modulus of elasticity of concrete is related to the structural stiffness and deformation process of concrete structures, and is highly sensitive to the cracking. The velocity of ultrasonic pulses travelling in a solid material depends on the density and elastic properties of that material. Non-destructive testing namely, dynamic modulus of elasticity and ultrasonic pulse velocity was measured for high strength concrete incorporating cementitious composites. Results of dynamic modulus of elasticity and ultrasonic pulse velocity are reported and their relationships with compressive strength are presented. It has been found that NDT is reasonably good and reliable tool to measure the property of concrete which also gives the fair indication of the compressive strength development.


2019 ◽  
Vol 970 ◽  
pp. 63-74
Author(s):  
Yuliya Shulgina ◽  
Maria A. Kostina ◽  
P.V. Sorokin ◽  
Marina Polonskaya ◽  
O.A. Kozhemyak ◽  
...  

Many industries apply pressure tanks for the storage of various types of liquids [1]. It can be toxic, chemically active liquids or food products. Storage conditions of these liquids can have a wide range of pressures and temperatures; therefore it is preferable to control the liquids levels from the outside of the tank. The most optimal solution in this case is the ultrasonic pulse time method [2-6], which is also widely used in robotics [7], fishing, shipping [8-9], archeology [10-11], non-destructive testing [12-17] and manometric method [18].


2018 ◽  
Vol 207 ◽  
pp. 01001
Author(s):  
Tu Quynh Loan Ngo ◽  
Yu-Ren Wang

In the construction industry, to evaluate the compressive strength of concrete, destructive and non-destructive testing methods are used. Non-destructive testing methods are preferable due to the fact that those methods do not destroy concrete samples. However, they usually give larger percentage of error than using destructive tests. Among the non-destructive testing methods, the ultrasonic pulse velocity test is the popular one because it is economic and very simple in operation. Using the ultrasonic pulse velocity test gives 20% MAPE more than using destructive tests. This paper aims to improve the ultrasonic pulse velocity test results in estimating the compressive strength of concrete using the help of artificial intelligent. To establish a better prediction model for the ultrasonic pulse velocity test, data collected from 312 cylinder of concrete samples are used to develop and validate the model. The research results provide valuable information when using the ultrasonic pulse velocity tests to the inputs data in addition with support vector machine by learning algorithms, and the actual compressive strengths are set as the target output data to train the model. The results show that both MAPEs for the linear and nonlinear regression models are 11.17% and 17.66% respectively. The MAPE for the support vector machine models is 11.02%. These research results can provide valuable information when using the ultrasonic pulse velocity test to estimate the compressive strength of concrete.


Author(s):  
F. Frey ◽  
E. Weidner

AbstractComplementary neutron and x-ray diffuse scattering may provide insight into structural super-ordering and disordering of decagonal quasicrystals (d-phases), and, in consequence, into the formation and stability of aperiodically ordered alloys. Neutron diffraction makes a contrasting almost isoelectronic atomic species possible, as well as a separation of elastic and inelastic diffuse intensity contributions. Experimental work at high temperatures is comparatively unproblematic. The method suffers, however, from the difficulty in obtaining sufficiently sized mono-grain samples and a lack of dedicated neutron diffraction instruments. Recent results, with a main focus on high-temperature (<1000°C) investigations of disordered decagonal Al—Ni—Co phases are reported and some tentative models are discussed.


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