Title

Ultrasonic Monitoring of the Early-Age Hydration of Mineral Admixtures Incorporated Concrete using Cement-Based Piezoelectric Composite Sensors

Abstract

The early-age hydration processes of concretes with mineral admixtures have been monitored and evaluated by a newly developed ultrasonic method based on embedded cement-based piezoelectric composite sensors. With the embedded ultrasonic (P-wave) measurement system, the waveform, wave velocity, attenuation coefficient index, and frequency-domain spectrum of detected ultrasonic waves during hydration can be recorded. The mineral admixtures examined include fly ash, slag, and silica fume, which replace part of the cement in concrete mixtures. It is found that the ultrasonic transmission parameters can be related to the microstructure changes of the concrete. Both the acceleration effects of silica fume and the retardation effects of fly ash and slag on the early hydration of concrete can be determined and explained through the analysis and comparison of the characteristics of the velocity curves. The attenuation coefficient index curve provides additional observation for the study of hydration kinetics. Moreover, the function of fresh concrete in filtering the high-frequency component of the wave varies with time, and concrete can be considered as low-pass frequency spectral filter. Frequency spectra analysis at different ages of fresh concrete provides useful information to reveal the early-age hydration process.

Department(s)

Civil, Architectural and Environmental Engineering

Keywords and Phrases

Acoustic Wave Velocity; Cements; Concrete Mixtures; Concretes; Fly Ash; Frequency Domain Analysis; Hydration; Low Pass Filters; Minerals; Piezoelectric Materials; Piezoelectricity; Seismic Waves; Silica; Silica Fume; Slags; Ultrasonic Measurement; Wave Propagation; Attenuation; Cement Based Piezoelectric Composite; Frequency Domains; Mineral Admixtures; Ultrasonic Monitoring; Wave Velocity; Concrete Additives

International Standard Serial Number (ISSN)

1045-389X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2015 SAGE Publications Ltd, All rights reserved.

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