Effects of air voids on ultrasonic wave propagation in early age cement pastes

Zhu, Jinying; Kee, Seong‐Hoon; Han, Di; Tsai, Yi-Te

doi:10.1016/j.cemconres.2011.04.005

Cited by 91 publications

(41 citation statements)

References 23 publications

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“…(3) The UPV method has not allowed to monitor the cement paste since the earliest ages (after mixing). It is estimated that the possible reasons may be associated with to the presence of air bubbles in the samples and to the high stiffness impedance between the transducers and the paste, particularly in the initial stage of the curing process (during setting), as was already mentioned by other authors (Zhu et al, 2011a). (4) In addition to the use of EMM-ARM, this study also presented stiffness evaluation through benderextender elements, which had only been applied to cement paste by Zhu et al (2011b).…”

Section: Discussionmentioning

confidence: 79%

“…The reason for this problem can be attributed to the presence of air bubbles in the samples, which have been reported to attenuate and delay the wave propagation, as well as due to the high impedance mismatch between the transducers and the fresh cement paste (Zhu et al 2011a). In fact, in order to monitor the evolution of the P-wave velocity in cement pastes, some authors (Boumiz et al 1996;Zhu et al 2011a) used de-aired samples (previously placed in vacuum) with successful results. However, since the cement pastes always contain some air bubbles the de-airing of the samples may end up producing unrealistic results.…”

Section: Ultrasonic Pulse Velocity (Upv)mentioning

confidence: 99%

“…However, acoustic methods have relevant limitations for concrete testing as these are quite sensitive to local effects caused by aggregates (Neville 1995). Moreover, it has been recognized that the air content in cementitious materials can have drastic effects on the reduction of longitudinal ultrasonic wave velocities since it causes a severe attenuation due to wave reflection (Zhu et al 2011a). Alternatively, Zhu and Kee (2010) have applied a methodology commonly used in soil characterisation to cement paste: bender-extender elements (BE) (Thomann and Hryciw 1990).…”

Section: Introductionmentioning

confidence: 99%

“…This paper is focused on non-destructive approaches for characterization of the cement paste hardening, particularly on setting and stiffness monitoring. To evaluate these properties, several non-destructive methods can be found in the literature, namely: mechanical methods (Chamrová 2010;Maia et al 2012b;Boulay et al 2010;Staquet et al 2012;Boulay et al 2013b); wave propagation methods (Voigt 2005;Reinhardt and Grosse 2004;Song et al 2008;Zhu and Kee 2010;Zhu et al 2011a;Zhu et al 2011b;Voigt et al 2005;Kim et al 2009); resonance methods (Kim et al 2009, Malhotra andSivasundaram 2003;Wang et al 2010;Shin et al 2008;Azenha et al 2012); and methods based on dielectric properties (Beek 2000Princigallo et al 2003). The Cyclic Compression (CC) method is the oldest and the most accepted method for characterizing the elastic modulus of concrete.…”

Section: Introductionmentioning

confidence: 99%

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Comparison Between Different Experimental Techniques for Stiffness Monitoring of Cement Pastes

Granja

Azenha

Sousa

et al. 2014

ACT

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In 2009, a new methodology for the continuous monitoring of E-modulus of cement-based materials since casting was proposed, under the designation EMM-ARM (E-modulus Measurement through Ambient Response Method). This methodology is a variant to classic resonant frequency methods that allows continuous stiffness monitoring from the instant of casting. After the encouraging results obtained in the first applications of EMM-ARM to cement pastes, the present paper gives continuity to previous developments, through validations with additional experimental methodologies and extension to thermal activation testing. At first, a comparison is performed between the results of EMM-ARM and those obtained through: pulse velocity methods (both ultrasonic contact probes and bender-extender elements), penetration resistance (Vicat needle) and cyclic compression on cylindrical specimens. Afterwards, the possibility of studying the activation energy of the stiffness evolution on tests conducted at 20ºC and 40ºC is explored.

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Section: Discussionmentioning

confidence: 79%

Section: Ultrasonic Pulse Velocity (Upv)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comparison Between Different Experimental Techniques for Stiffness Monitoring of Cement Pastes

Granja

Azenha

Sousa

et al. 2014

ACT

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“…More recent studies have used ultrasound techniques to quantify the amount of air voids in both hardened concrete (20)(21)(22) and fresh cement pastes (23,24). The ultrasonic techniques have also been used for the prognostic and diagnostic monitoring of near surface concrete (25).…”

Section: Ultrasonic Characterization Techniquesmentioning

confidence: 99%

Feasibility Study of In-situ Characterization of Size Distribution of Air Voids in Concrete Pavements

Li¹,

Tong²,

Liu³

2013

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The Joint Transportation Research Program serves as a vehicle for INDOT collaboration with higher education institutions and industry in Indiana to facilitate innovation that results in continuous improvement in the planning, design, construction, operation, management and economic efficiency of the Indiana transportation infrastructure. https://engineering.purdue.edu/JTRP/index_html AbstractThis report concerns a feasibility study on the use of a non-destructive and non-invasive method to determine the size distribution of air voids in fresh concrete, which will be used for laying concrete pavement. A preliminary review of different techniques suggested that the measurement of the p-wave velocity of ultrasound pulses transmitted through a fresh concrete specimen offers the most straightforward approach. This report describes an experimental study to address the design of an experimental test rig, the selection of appropriate equipment, and the determination of the p-wave velocity in fresh cementitious materials. The paper starts with the ultrasound characterization of fresh cement and mortars. Then, the feasibility of using the ultrasound method to determine the air-void content in a fresh concrete specimen with a minimum thickness of 4" is examined. In addition to the discussions of the ultrasound characterization of fresh cementitious materials, this paper also reports on the development of a suite of MATLAB programs to characterize the air-void systems of hardened cementitious materials. The approach is based on image processing techniques used to analyze digital images of polished specimens collected with a flatbed scanner. The results will provide pertinent information on the airvoid systems in hardened cementititous materials. 17.

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