Review of Ultrasonic Wave Reflection Applied to Early-Age Concrete and Cementitious Materials

Abstract

The ultrasonic wave reflection method, as applied to characterize early age cement-based materials, is reviewed. The topic is first introduced with a historical review of method development. The theoretical basis of the reflection technique within the context of wave mechanics is then considered, followed by a description of experimental techniques and associated requirements of testing setups. Then fundamental background information about the method is described, including effects of ultrasonic wave mode (compression and shear waves) and buffer material (metal, ceramic and polymer) on the results and required experimental apparatus. Several test application tasks, across a range of cementitious material ages (hydration states), are summarized, including determination of global constitutive properties, estimation of setting time (initial and final sets), evolution of strength, and assessment of microstructure (e.g. flocculation state in setting material and porosity in solid material). The analyses of various techniques are presented in a unified manner for elastic, viscoelastic and poroelastic idealizations of the cementitious material.

Non-Destructive Study of the Microstructural Effects of Sodium and Magnesium Sulphate Attack on Mortars Containing Silica Fume Using Impedance Spectroscopy

“…Currently, the use of non-destructive techniques for characterizing the microstructure of cement-based materials has become an important research field [1][2][3][4][5][6][7]. Among these techniques, impedance spectroscopy has been greatly developed during the last few years.…”

“…It has been suggested that among the most typical associated cations, calcium and sodium are innocuous, while magnesium is aggressive [20]. On one hand, the chemical reactions produced by the sodium sulphate attack are shown in Equations (1) and (2). The reaction shown in Equation 2produces the formation of expansive ettringite crystals.…”

Sodium silicate activated slag‐fly ash binders: Part III—Composition of soft gel and calorimetry

“…Since penetration testing has some drawbacks, shear wave ultrasonic wave reflectometry (SUWR), was used in addition to the ASTM C403 penetration test to study the setting time of SFBs, as recommended by Suraneni et al The theory and experimental set‐up have been discussed elsewhere . In this method, the intensity of the wave reflected at the interface of a buffer and sample is monitored as a function of time . Because shear waves (s‐waves) propagate in solids but not in fluids, there is a marked increase in the intensity of the propagated wave, and, thereby, decrease in the intensity of the reflected wave, as setting takes place .…”

Concrete Defects Sizing by Means of Ultrasonic Velocity Maps

“…Several studies related to the application of UT to concrete can be addressed. Main topics are the evaluation of concrete early-stage properties [19][20][21][22][23][24], the assessment of physical and mechanical properties [25][26][27][28][29][30][31][32], and the evaluation of damage [33][34][35][36][37][38][39][40]. Despite the large amount of contributions, the performance of UT in field on on-site concrete is still questionable and needs to be validated.…”