Search query: Ultrasonic testing of concrete

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abstract: This paper provides design and development details of the generation of bipolar High Voltage (HV) square wave pulses for the excitation of low frequency ultrasonic transducers. Such a circuit is required for the purpose of ultrasonic inspection of components, particularly where high energy is required to insonify the attenuative medium, such as concrete. A HV 350 V) square wave pulse has been generated by an ultrafast complementary Metal Oxide Semiconductor Field Effect Transistor (MOSFET) pair, which is driven by high speed MOSFET drivers. The generated bipolar square wave pulse has been utilized to energize a 108 kHz ultrasonic transducer to operate in the pulse echo mode for the evaluation of a concrete test block. The receiver amplifier filters the received low amplitude echo signals, which are reflected back from a discontinuity, and amplifies further for signal to noise ratio enhancement. The pulser board designed has been tested and evaluated for its functionality to measure ultrasonic velocity in the highly attenuative concrete medium up to a depth of 1 m. The measured value of acoustic velocity was compared with the value obtained from the commercially available ultrasonic pulse velocity instrument, and the values obtained are within 5%
author_names: Harshit Jain

Eaglekumar G Tarpara

Vikram Patankar
title: Design and development of ultrasonic bipolar square wave pulser for non destructive testing of concrete structures.
venue: The Review of scientific instruments
year: 2020

abstract: The health state of concrete is deteriorating during its service. Nonlinear ultrasonic detection based on the amplitude of the fundamental and the second harmonic is considered to be a powerful tool for the discovery of the microcrack in concrete. However, the research on processing the nonlinear ultrasonic signal is still insufficient. In order to highlight the real frequency domain components in the nonlinear ultrasonic signal, wavelet and ensemble empirical mode decomposition (EEMD) were joined to denoise the numerical and measured signal. The optimal wavelet base and the decomposition level were determined by the signal to noise ratios (SNRs) Then, the wavelet threshold denoising signal was decomposed by EEMD, omitting the high frequency components and ultimately achieving the desired denoising effect. The denoising result of the test signals demonstrates that this method is effective in denoising the details of the ultrasonic signal and improving the reliability and adaptability of the nonlinear ultrasonic testing. In this experiment, the concrete with the microcrack was tested by linear and nonlinear ultrasonic methods. Based on the variation regularity of the nonlinear ultrasonic coefficient and velocity we can conclude that the nonlinear ultrasonic parameter is more sensitive to the microcrack in concrete than the traditional wave velocity The nonlinear ultrasonic testing can be an important supplement to the current nondestructive testing technique of the concrete.
author_names: Zhichao Nie

Kui-Fang Wang

Mingjie Zhao
title: Application of Wavelet and EEMD Joint Denoising in Nonlinear Ultrasonic Testing of Concrete
year: 2018

abstract: Based on the urban shantytown renovation project in Hongguang Town, Helan County, Ningxia, in Northwest China, the influence of fly ash and silica fume admixture on the mechanical properties of Self compacting Concrete (SCC) was tested and analyzed in this work. The experimental tests including compressive strength, splitting strength, triaxial strength and an ultrasonic nondestructive test. Furthermore, the Back Propagation (BP) neural network algorithms were established. The results show that there is an obvious difference between the development law of compressive strength of SCC and that of ordinary concrete. The splitting pressure ratio of SCC is 1/10 to 1/8, while that of ordinary concrete is 1/13 to 1/10. Moreover, the peak strain, peak stress and initial stiffness of SCC increase with the increase of the confining pressure when compressed from three directions. In addition, the ultrasonic amplitude of SCC can reflect the changing laws of its compressive strength. As a conclusion, the addition of fly ash and silica fume increases the splitting pressure ratio of SCC. More importantly, the compressive strength formula for SCC with silica fume and a low content of fly ash is proposed, and the model equation between the amplitude and compressive strength is given. This study provides a reference for the mixture ratio of fly ash and silica fume in the application of SCC.
author_names: Hongbo Li

Hao Yue Sun

Juncang Tian

Qiuning Yang

Qingqing Wan
title: Mechanical and Ultrasonic Testing of Self Compacting Concrete
venue: Energies
year: 2019

abstract: Ultrasonic testing analysis is a crucial scientific component during the process and interpretation of the ultrasonic detection signal. Focusing on the ultrasonic testing characteristics, the time invariant spectral analysis method cannot meet the processing requirements of the detection signal fully. Thus, S transform, the time varying analysis method, was introduced into the ultrasonic testing data processing of the concrete structure. The acoustic wave phase velocity was derived based on the spectrum analysis, and the S transform time frequency analysis method was established. Finally, based on the method of concrete experimental data set, studies show that the frequency energy spectrum with S transform can realize flexible and effective identification of defects in the concrete structure. Definitely, this analysis method can significantly improve the resolution and practicality of ultrasonic testing.
author_names: Juncai Xu

Hai Wei
title: Ultrasonic Testing Analysis of Concrete Structure Based on S Transform
venue: Shock and Vibration
year: 2019

abstract: &NA; The use of nonlinear acoustic techniques in solids consists in measuring wave distortion arising from compliant features such as cracks, soft intergrain bonds and dislocations. As such, they provide very powerful nondestructive tools to monitor the onset of damage within materials. In particular, a recent technique called dynamic acousto elasticity testing (DAET) gives unprecedented details on the nonlinear elastic response of materials (classical and non classical nonlinear features including hysteresis, transient elastic softening and slow relaxation) Here, we provide a comprehensive set of linear and nonlinear acoustic responses on two prismatic concrete specimens; one intact and one pre compressed to about 70% of its ultimate strength. The two linear techniques used are Ultrasonic Pulse Velocity (UPV) and Resonance Ultrasound Spectroscopy (RUS) while the nonlinear ones include DAET (fast and slow dynamics) as well as Nonlinear Resonance Ultrasound Spectroscopy (NRUS) In addition, the DAET results correspond to a configuration where the (incoherent) coda portion of the ultrasonic record is used to probe the samples, as opposed to a (coherent) first arrival wave in standard DAET tests. We find that the two visually identical specimens are indistinguishable based on parameters measured by linear techniques (UPV and RUS) On the contrary, the extracted nonlinear parameters from NRUS and DAET are consistent and orders of magnitude greater for the damaged specimen than those for the intact one. This compiled set of linear and nonlinear ultrasonic testing data including the most advanced technique (DAET) provides a benchmark comparison for their use in the field of material characterization. HighlightsThe results from a suite of linear and nonlinear ultrasonic techniques are compared.Dynamic Acousto Elastic Testing (DAET) with a coda wave probe is presented.The retrieved non log(t) recovery at early times provides complementary information.
author_names: Parisa Shokouhi

Jacques Riviere

Colton R Lake

Pierre-Yves Le Bas

Timothy Ulrich
title: Dynamic acousto elastic testing of concrete with a coda wave probe: comparison with standard linear and nonlinear ultrasonic techniques
venue: Ultrasonics
year: 2017

abstract: This paper discusses the possibility of studying composite materials by non destructive laser ultrasonic testing technique. Concrete samples and carbon epoxy composites were examined, defects located and elastic wave velocities measured. The internal structure of the samples was visualized in 2D images.
author_names: Alexander Kravcov

Pavel Svoboda

Adam Konvalinka

Elena Cherepetskaya

Alexsander A Karabutov

Dmitry Vladimirovich Morozov

I A Shibaev
title: Laser Ultrasonic Testing of the Structure and Properties of Concrete and Carbon Fiber Reinforced Plastics
year: 2016

abstract: Abstract The ultrasonic fatigue testing method has been further developed to perform cyclic compression tests with concrete. Cylindrical specimens vibrate in resonance at a frequency of approximately 20 kHz with superimposed compressive static loads. The high testing frequency allows time saving investigations in the very high cycle fatigue regime. Fatigue tests were carried out on "Concrete 1" (compressive strength fc 80 MPa) and "Concrete 2" (fc 107 MPa) under purely compressive loading conditions. Experiments at maximum compressive stresses of 0.44 fc (Concrete 1) and 0.38 fc (Concrete 2) delivered specimen failures above 109 cycles, indicating that no fatigue limit exists for concrete below one billion load cycles. Resonance frequency, power required to resonate the specimen and second order harmonics of the vibration are used to monitor fatigue damage in situ. Specimens were scanned by X ray computed tomography prior to and after testing. Fatigue cracks were produced by ultrasonic cycling in the very high cycle fatigue regime at interfaces of grains as well as in cement. The possibilities as well as limitations of ultrasonic fatigue testing of concrete are discussed.
author_names: Ulrike Karr

Reinhard Schuller

Michael Fitzka

Andreas Denk

Alfred Strauss

Herwig Mayer
title: Very high cycle fatigue testing of concrete using ultrasonic cycling
year: 2017

abstract: This paper presents the results of preliminary laboratory testing of early age concrete properties using disposable, embedded ultrasonic sensors. These tests were carried out during the development of a field system for monitoring the early age physical properties in concrete and shotcrete. The design is particularly suitable for applications in Fibre Reinforced Shotcrete (FRS) commonly used for ground support in underground mine tunnels in Australia, where the determination of early age properties is critical for establishing safe re entry times. The embedded system used in these experiments comprises a pair of piezoelectric transducers mounted to an open frame, which is designed to hold them within the concrete at a fixed offset separation. The probe is implanted at the time of placement, and connected via wire leads to an external control system. The implanted transducers are configured to excite longitudinal (P) waves, at a nominal resonance frequency of 40 kHz, and P wave transmission is detectable soon after the initial set time. The data presented herein includes evolution of early age P wave velocity. This data is compared to conventional unconfined compressive strength (UCS) and dynamic (low strain) elastic modulus, as specified in ASTM C215, for equivalent batches and curing conditions. The embedded P wave measurement is functionally equivalent to the conventional dynamic modulus testing procedure, and these results may be further used to infer UCS during the early stages of hydration. The ability to perform in situ, real time, nondestructive testing offers significant advantages to the safe and efficient use of FRS in underground mining applications.
author_names: Alexander Gibson

Daniela Ciancio
title: Early Age Ultrasonic Testing of Concrete and Shotcrete using Embedded Sensors
year: 2013

author_names: Jason Maximino C Ongpeng

Andres Oreta

Sohichi Hirose
title: Characterization of Damage Using Ultrasonic Testing on Different Types of Concrete
year: 2018

abstract: Synopsis Ultrasonic testing of a reinforced concrete member by means of the Pundit apparatus is affected by the steel bars embedded in the concrete. An investigation of the effects of the reinforcement has been made, using the bar diameter and the concrete strength as the variables. It is found that the steel bar appears to act compositely with the surrounding concrete in transmitting ultrasonic pulses. The effective pulse velocity is somewhat between the pulse velocities in the two separate media, and varies with the diameter of the bar and the pulse velocity in the concrete. An empirical formula for the effective pulse velocity is proposed. On the basis of this formula and further theoretical consideration, the zone of steel influence is defined. A correction factor is derived whereby the measured pulse velocity in a concrete steel medium is adjusted to give the pulse velocity in the plain concrete.
author_names: H W Chung
title: Effects of embedded steel bars upon ultrasonic testing of concrete
year: 1978