scholarly journals Ultrasonic wave propagation in thermally treated concrete up to 400 ºC

Author(s):  
Ana Carolina Costa Viana ◽  
Poliana Dias de Moraes ◽  
Ivo José Padaratz

Abstract The ultrasonic pulse velocity, obtained by ultrasonic non-destructive testing, has been applied to evaluate the concrete integrity. The attenuation parameters have shown more sensitivity to damage detection in the microstructure of concrete since they consider the entire ultrasonic waveform. However, it is still necessary to evaluate the sensitivity of those parameters to thermally damaged concrete. This work aims to assess the behavior and the sensitivity of the following ultrasonic parameters: pulse and group velocities, maximum amplitude, total energy, accumulated energy, and time instants corresponding to 25%, 50%, and 75% of the energy, in detecting changes due to thermal degradation of the concrete. A sample of 39 cylindrical concrete specimens with 100 mm in diameter and 300 mm in length and C25 strength class was used. The sample was distributed into 5 groups heated between 20 and 400 ºC until the internal temperature of the specimens became homogeneous. The groups were cooled inside a muffle furnace until reaching 150 ºC. Subsequently, they were exposed to the ambient temperature and humidity of the laboratory environment for, at least, 24 hours prior to the tests of mass loss, ultrasound, and compressive strength. The results show that the ultrasonic parameters are sensitive to the thermal degradation of the concrete. The pulse velocity, the accumulated energy, and the time instants corresponding to percentages of the energy decrease monotonically as the temperature increases. The group velocity shows significant dispersions, while the maximum amplitude and the total energy increase at 200 ºC. The results led to the conclusion that the pulse velocity is the least sensitive parameter, while the time instants corresponding to 25%, 50%, and 75% of the energy are the most sensitive parameters in detecting changes due to thermal degradation of the concrete.

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.


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.


2021 ◽  
Vol 1164 ◽  
pp. 77-86
Author(s):  
Bogdan Bolborea ◽  
Sorin Dan ◽  
Claudiu Matei ◽  
Aurelian Gruin ◽  
Cornelia Baeră ◽  
...  

Developing a non-destructive method which delivers fast, accurate and non-invasive results regarding the concrete compressive strength, is an important issue, currently investigated by many researchers all over the world. Different methodologies, like using the simple non-destructive testing (NDT) or the fusion of different techniques approach, were taken into consideration in order to find the optimal, most suitable method. The purpose of this paper is to present a new approach in this direction. The methodology consists in predicting the concrete compressive strength through ultrasonic testing, for non-destructive determination of the dynamic and static moduli of elasticity. One important, basic assumption of the proposed methodology considers values provided by technical literature for concrete dynamic Poisson’s coefficient. The air-dry density was experimentally determined on concrete cores. The dynamic modulus of elasticity was also experimentally determined by using the ultrasonic pulse velocity (UPV) method on concrete cores. Further on, the static modulus of elasticity and the concrete compressive strength can be mathematically calculated, by using the previously mentioned parameters. The experimental procedures were performed on concrete specimens, namely concrete cores extracted from the raft foundation of a multistorey building; initially they were subjected to the specific NDT, namely ultrasonic testing, and the validation of the results and the proposed methodology derives from the destructive testing of the specimens. The destructive testing is generally recognized as the most trustable method. The precision of the proposed method, established with respect to the destructive testing, revealed a high level of confidence, exceeding 90% (as mean value). It was noticed that even the cores with compressive strength outside of mean range interval (minimum and maximum values) presented high rate of precision, not influencing the overall result. The high rate of accuracy makes this method a suitable research background for further investigations, in order to establish a reliable NDT methodology which could substitute the very invasive and less convenient, destructive method.


2018 ◽  
Vol 792 ◽  
pp. 166-169
Author(s):  
Yu Ren Wang ◽  
Loan T.Q. Ngo ◽  
Yi Fan Shih ◽  
Yen Ling Lu ◽  
Yi Ming Chen

SONREB method is a non-destructive testing (NDT) method for estimating the concrete compressive strength. It is conducted by combining two popular NDT methods: ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Several researches have been attempted to find the correlation of the different testing method data with actual compressive strength. This research proposes a new Artificial Intelligence based approach, Artificial Neural Networks (ANNs), to estimate the concrete compressive strength using the UPV and RH test data. Data from a total of 315 cylinder concrete samples are collected to develop and validate the ANFIS prediction model. The model prediction results are compared with actual compressive strength using mean absolute percentage error (MAPE). With the adaption of ANFIS, the estimation error of SONREB test can be reduced to 5.98% (measured by MAPE).


2021 ◽  
Vol 1197 (1) ◽  
pp. 012054
Author(s):  
Ragini Kondalkar ◽  
Nikhil H. Pitale ◽  
K.R. Dabhekar ◽  
D.P. Mase

Abstract In India there are infinite old structures that are at the verge of damages. There are many buildings which have reduced their strength due to time passes, due to deterioration of concrete from structural element, due to development of cracks. The structure is a combination of load carrying members, damages in members cause failure of structure and it is harmful for living beings. To prevent old structure from failure the technique is adopted know as Non-Destructive Testing (NDT). With the help of non-destructive testing auditing of an old structure is get easier. NDT examine the total health of an infrastructure in order to check strength and stability of building. NDT is a bunch of various testing consist of Ultrasonic pulse velocity test (UPV), Rebound hammer test (RHT), Half-cell test, etc. Conducting NDT on building and analyzing testing result decide to repair building as per IS code, technique like grouting, Retrofitting, etc. to increase strength and stability of building. In this project structural has to be done on old structure which is situated at Nagpur. Audit done by NDT consist of Ultra-sonic pulse velocity test, Rebound hammer test, Half-cell test. After analyzing all test result including visual inspection it is found that structure need to repair and retrofitted to make it safe and stable for all static loadings. Column jacketing also provide to structure.


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.


2021 ◽  
Vol 45 (5) ◽  
pp. 361-368
Author(s):  
Messaouda Belouadah ◽  
Zine Elabidine Rahmouni ◽  
Nadia Tebbal ◽  
Mokrani El Hassen Hicham

The present study aims primarily to investigate the possibility of assessing the physico-mechanical behavior of concrete incorporating marble waste or marble powder as a partial replacement for cement using destructive and non-destructive testing methods. Indeed, in this work, cement was partially replaced with marble powder at six different substitution levels, i.e. 5, 10, 15, 20, 25 and 30% by weight, with 1.5% adjuvant (super plasticizer) for each mixture. The samples prepared were then analyzed. In addition, the physico-mechanical properties, in the fresh and hardened states, water-to-cement ratio, absorption and compressive strengths of the concrete samples were examined as well. Moreover, the compressive strength of concrete was assessed through non-destructive testing methods such as the ultrasonic pulse velocity and rebound hammer. Likewise, the relationship between the ultrasound velocity and compressive strength of concrete were also estimated after 3, 7, 28 and 90 days of curing. The findings of the study indicated that, at early age of curing, the values of the compressive strength and ultrasonic pulse velocity were quite small for all replacement levels, of cement with marble powder, between 15 and 30%. Nevertheless, when the curing period was increased, the compressive strength and ultrasonic pulse velocity of all the samples went up as well. In the end, a linear relationship was observed between the ultrasonic pulse velocity and compressive strength for all substitution levels of cement with marble powder.


Author(s):  
Adan Bishar Hussein ◽  
Mohamed Abdi

This paper aims to respond to these concerns through the identification and explanation of the most popular and effective NDT approaches in concrete structures and also their accuracies. The fundamentals of the non-destructive test methods are discussed in terms of their capacity, limits, inspection techniques and interpretations. Factors that affect the performance of NDT an approach are discussed and means of mediate their influence was suggested. Ultrasonic pulse velocity and SONREB methods of Non-destructive test are showed in this paper as past experiments of NDT. NDT of concrete was found to be increasingly recognized as a way of measuring the strength, integrity, resilience and other properties of existing concrete structures, Perceptions of NDT inadequacy are attributed to lack of knowledge of the building materials and the NDT approaches themselves. The goal of this paper is to resolve these issues reviewing some articles already done and defining and discussing the most common popular NDT methods applied to concrete structures.


2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Tuba Bahtlı ◽  
Nesibe Sevde Özbay

In this study, the effects of finely-milled bronze and waste tire on the mechanical properties of concrete have been investigated. Approximately 2.5% and 5% by weight for each additive (bronze sawdust and waste tire) were added to dry concrete. The open porosity, density, compressive strength values of cured concrete have been determined. In addition, the Schmidt rebound hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, were applied. The microstructure and fracture surfaces of these materials were characterized by scanning electron microscopy (SEM). It was observed that the density of pure concrete was 2.35 g/cm3 while the density was 2.19 g/cm3 for a C+5%B+5%T material. Similarly, pure concrete had an almost three times better compressive strength and a two times better SRH value than those of the C+5%B+5%T material. The density and mechanical properties of concrete materials containing bronze and waste tire decreased due to micro crack formations, weak bonding and deep cracks forming especially between the concrete and additives.


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