Humidity and aggregate content correction factors for air-coupled ultrasonic evaluation of concrete

Berriman, James Robert Stockwell; Purnell, Phil; Hutchins, David A.; Neild, Adrian

doi:10.1016/j.ultras.2004.07.003

Cited by 38 publications

(22 citation statements)

References 19 publications

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“…Pulse compression has recently been used with broadband aircoupled transducers, where energy transmission, signal-to-noise ratio (SNR), and TOF accuracy are relatively low compared with conventional direct coupled ultrasound. 5,6,7,8 Gan et al 6 found that pulse compression provided the air-coupled system with the ability to detect received pulses even when they were well below the noise floor due to the frequency encoded transmitted pulse. In addition, they were able to resolve closelyspaced return echoes from various reflection sources with high accuracy, which was not possible with typical ultrasonic tone burst or square wave excitation technologies.…”

Section: Figure 1 the Container Screening Device (Csd) Alpha Unitmentioning

confidence: 99%

Through-container measurement of acoustic signatures for classification/discrimination of liquid explosives (LEs) and precursor threat liquids

et al. 2008

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Work at the Pacific Northwest National Laboratory has demonstrated that ultrasonic property measurements can be effectively employed for the rapid and accurate classification/discrimination of liquids in small, carryon, standard "stream-of-commerce" containers. This paper focuses on a set of laboratory measurements acquired with the PNNL prototype device as applied to several types of liquids (including threat liquids and precursor chemicals) to the manufacture of LEs in small commercially available plastic containers.

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Section: Figure 1 the Container Screening Device (Csd) Alpha Unitmentioning

confidence: 99%

Through-container measurement of acoustic signatures for classification/discrimination of liquid explosives (LEs) and precursor threat liquids

et al. 2008

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“…Cross-correlation between the transmitted pulse and the received pulses results in a waveform containing the same time, amplitude, and spectral information as the received pulse (amplitude and frequency information is preserved). Pulse compression has recently been used with broadband air-coupled transducers, where energy transmission, SNR, and TOF accuracy are relatively low compared with conventional direct-coupled ultrasound (Gan et al 2001a;Gan et al 2001b;Gan et al 2004;Berriman et al 2005). Gan et al (2001a) found that pulse compression provided the air-coupled system with the ability to detect received pulses even when they were well below the noise floor due to the frequency-encoded transmitted pulse.…”

Section: Technical Backgroundmentioning

confidence: 99%

Density and Flow-Velocity Measurement Technology for Dredging Applications - Proof of Concept Study

Greenwood¹,

Tucker²,

Diaz³

2004

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SummaryThe U.S. Army Corps of Engineers (USACoE) is searching for advanced technologies to provide physical property information about the dredge slurry traveling through the pipe in real-time, including density and the flow rate of the slurry. During the latter part of FY07, the USACoE funded a proof-ofconcept study at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, to investigate potential technical solutions to this problem by evaluating the viability of a patented acoustic method for measuring density and the advanced measurement approach employed using pulsecompression acoustics. A trip to Coos Bay, Oregon, was taken by PNNL staff in mid-August to observe the operation of the USACoE dredger ship Essayons, which dredges sand from the ocean floor and to acquire samples of dredge slurry material extracted from the Bay for use in this study.PNNL staff conducted a proof-of-concept evaluation study on these dredge slurry samples to determine the viability for eventual design and testing of an ultrasonic density sensor and flow meter. Two sets of trials were conducted in this study: 1) basic ultrasonic property measurements and signal transmission trials in through-transmission mode using both mono-frequency tone-burst and pulsecompression approaches, and 2) real-time density measurements. This technical letter report provides a summary of the work conducted and the results obtained, and documents the conclusions and recommendations from this proof-of-concept evaluation.The Essayons employs both a radioactive density sensor and a sonic flow meter; both commercially available devices. The current density sensor operates and performs satisfactorily, but the USACoE wants to replace these technologies, especially the density sensor, due to cost, maintenance and security protocols, and paperwork issues associated with their use. The operation of the current sonic flow meter can be problematic.Although the ultrasonic pulse-compression technique could not penetrate the slurry generated in the laboratory setup, the results are still inconclusive due to the large amount of air introduced into the slurry as a result of the mixing process required for particle suspension. The conditions seen in the laboratory may not be representative of the slurry conditions generated in a pipe from dredge material pulled from the sea floor during routine dredging operations. It is anticipated that a pair of transducers placed on the outside of the dredge piping may demonstrate successful penetration of the slurry and allow for observable waveforms to accurately measure wave speed and relative attenuation, which are linearly related to the density of the slurry. This would allow for an alternate indication of specific gravity to the radiation density measurement currently used, and provide a means for measurement of flow rate using through-transmission methods. Further study onboard a dredging ship is recommended.Data were obtained using the PNNL ultrasonic density sensor for sand slurries having a density of 1.17 ...

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“…Conociendo que la resistencia del concreto depende entre otros factores del tipo de agregados pétreos utilizados en su elaboración [4,5], se plantea hallar una correlación estadística apropiada entre el pulso ultrasónico y el ensayo a compresión del concreto simple con diferentes tipos de agregados de la región de Córdoba para diferentes resistencias, específicamen-te de la ciudad capital Montería, la cual presenta una actividad constructora en auge y que también cuenta con construcciones vetustas declaradas patrimonio arquitectónico y que por lo tanto deberán potencializarse para cumplir con el reglamento colombiano de construcción sismo resistente (NSR -10) [6]. La ciudad está asentada a orillas del Río Sinú, el cual proporciona unos excelentes agregados pétreos (canto rodado y arena de alto módulo de finura), para la actividad constructora que tradicionalmente se han utilizado con una dosificación en volumen de 1:2:3 consiguiéndose fácilmente unas resistencias superiores a los 28 MPa.…”

Section: Introductionunclassified

Relación entre los ensayos ultrasónico y convencional para determinar la resistencia del concreto simple a la compresión

et al. 2016

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Humidity and aggregate content correction factors for air-coupled ultrasonic evaluation of concrete

Cited by 38 publications

References 19 publications

Through-container measurement of acoustic signatures for classification/discrimination of liquid explosives (LEs) and precursor threat liquids

Through-container measurement of acoustic signatures for classification/discrimination of liquid explosives (LEs) and precursor threat liquids

Density and Flow-Velocity Measurement Technology for Dredging Applications - Proof of Concept Study

Relación entre los ensayos ultrasónico y convencional para determinar la resistencia del concreto simple a la compresión

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