Monitoring Early Age Properties of Cementitious Material Using Ultrasonic Guided Waves in Embedded Rebar

Sun, Hongbin; Zhu, Jinying

doi:10.1007/s10921-016-0383-3

Cited by 16 publications

(12 citation statements)

References 13 publications

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“…Specially, after the very early age, there is an approximately linear relationship between these two measurements. Similar relationships, obtained by using steel rod for guide wave propagation, were also found in the hardening process monitoring of epoxy resins [33] and cement pastes [34].…”

Section: Normalized Amplitudesupporting

confidence: 78%

“…As seen in Figure 7 a, the central frequency of the reflected echoes obtained from the 6.35 mm diameter steel rod is 135 kHz, corresponding to a frequency-radius product of 428.63 kHz-mm. Sun [ 34 ] has proposed an improved approach to calculate the group velocity dispersion curve of rebar embedded into concrete, based on the PCDISP package [ 35 ]. By using Sun’s approach, the theoretical group velocity in steel rod with a frequency-radius product of 428.63 kHz-mm was found to be 4989 m/s.…”

Section: Resultsmentioning

confidence: 99%

“…It was found that both methods are sensitive to the shear properties at low frequencies. Sun and Zhu [ 34 ] improved the dispersion calculation of the embedded rebar and used the embedded rebar for guide wave propagation to monitor the early age properties of cement and mortar samples, and in this study the guided wave was generated using an electric coil and received by a commercial ultrasonic transducer. However, to the authors’ knowledge, only a steel rebar or wire with a fixed diameter was investigated in the studies above; it would be interesting to make comparisons between rods of different materials and diameters.…”

Section: Introductionmentioning

confidence: 99%

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Monitoring the Setting Process of Cementitious Materials Using Guided Waves in Thin Rods

Wang

Liu

et al. 2021

Materials

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Characterizing early-age properties is very important for the quality control and durability of cementitious materials. In this paper, an approach using embedded guided waves was adopted to monitor the changes in the mechanical proprieties of mortar and concrete during setting, and embedded thin rods with low-cost piezoelectric sensors mounted on top were used for guide wave monitoring. Through continuous attenuation monitoring of the guided waves, the evolution of mortar and concrete properties was characterized. Four different kinds of metallic rods were tested at the same time to find out the optimal setup. Meanwhile, shear wave velocities of the mortar and concrete samples were monitored and correlated to the attenuation, and setting time tests were also performed on these samples. Experimental results demonstrate that the proposed approach could monitor the evolution of the setting of cementitious materials quantitatively, and time of the initial setting could be determined by this technique as well. In addition, it is found that the attenuations of fundamental longitudinal guided wave mode are almost the same in concrete samples and mortar samples sieved from concrete, indicating that this technique is able to eliminate the effects of coarse aggregates, which makes it of great potential for in-situ monitoring of early age concrete.

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Section: Normalized Amplitudesupporting

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Monitoring the Setting Process of Cementitious Materials Using Guided Waves in Thin Rods

Wang

Liu

et al. 2021

Materials

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“…The amplitude of the mechanical wave at the distance l 2 depending on the amplitude at the distance l 1 can be expressed using the following equation:

A_{2} = A_{1} e^{- k_{ω} ((), l_{2} - l_{1})} = A_{1} e^{- k_{ω} ∆ l},

where k ω is absorption attenuation coefficient of stress waves in concrete. Equation can be expressed in the following way, as well:

italicln ((), \frac{A_{1}}{A_{2}}) = k_{ω} ∆ l .

…”

Section: Application Of Hybrid Approach On Square Platesmentioning

confidence: 99%

Experimental and numerical research on damage localization in plate-like concrete structures using hybrid approach

Stojić

Nestorović

Marković

et al. 2018

Struct Control Health Monit

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This paper presents an experimental–numerical analysis of damage localization of concrete plate‐like elements on the basis of hybrid approach. The proposed hybrid approach uses the fast discrete wavelet transform, energy approach, and time of flight criterion for the purpose of localization of single and multidamage problems inside or on the periphery of concrete elements. Verification of the proposed damage localization approach has been performed under laboratory conditions using a laser scanning‐based system with piezoelectric excitation of the wave propagation. Numerical simulation of the wave propagation is performed using the explicit finite element method using 3D models with linear‐elastic material model of concrete with Rayleigh damping. The Rayleigh damping coefficients are determined on the basis of experimental data and implemented in numerical models. Validation of the numerical model is conducted, based on the comparison with sensor output signals obtained through experimental measuring and a very good agreement of results is obtained. The proposed hybrid approach to damage localization is verified using 15 different models/specimens, varying the number, shape (circular or notched), and position of damage, as well as the number and placement of actuators/sensors. For all the analyzed scenarios, the hybrid approach successfully localized the damage even for the least number of used sensor positions. In the models with the circular damage, the damage image created on the basis of the hybrid approach is almost identical to the actual shape of the damage, indicating a good potential of the method for damage localization.

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“…The early age of cement has also been of great interest for the scientific world. Methods such as pulse velocity and the ultrasonic wave reflection have been widely used characterize early stage properties of cement [ 22 ]. Guided wave testing is a very interesting method for large range applications e.g.…”

Section: Introductionmentioning

confidence: 99%

A Methodology Based on Pulse-Velocity Measurements to Quantify the Chemical Degradation Levels in Thin Mortar Specimens

et al. 2018

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In this research, ultrasonic pulse echo measurements are used to quantify through thickness chemical degradation in thin mortar specimens. The degradation level is predicted using the time of travel of the acoustic wave through the thickness of the structure. The front and back wall interaction reflections are used to obtain additional information from very early stage degradation. The pulse-velocity of sound waves as a function of the thickness of the layers within the structure is described. With knowledge of the pulse-velocity in pristine and fully degraded conditions, it is possible to determine the complete range of degradation length over the layer thickness. The method is applicable for leaching of calcium and acidic attack. The acoustic measurements were verified with destructive testing. The correlation between the acoustic and non-acoustic experiments agree with the described pulse-velocity and degraded depth function. The method based on ultrasonic measurements can be implemented in other thin-layered structures.

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Monitoring Early Age Properties of Cementitious Material Using Ultrasonic Guided Waves in Embedded Rebar

Cited by 16 publications

References 13 publications

Monitoring the Setting Process of Cementitious Materials Using Guided Waves in Thin Rods

Monitoring the Setting Process of Cementitious Materials Using Guided Waves in Thin Rods

Experimental and numerical research on damage localization in plate-like concrete structures using hybrid approach

A Methodology Based on Pulse-Velocity Measurements to Quantify the Chemical Degradation Levels in Thin Mortar Specimens

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