The use of acoustic methods to describe the behaviour of cement pastes in the early stage of ageing

The use of acoustic methods to describe the behaviour of cement pastes in the early stage of ageing

Paper in proceedings outside WoS and Scopus

Monitoring of properties of cement-based composites at an early age (approximately during the first 48 hours after mixing cement with water), understanding the hydration processes of the cement paste, and identifying various mechanisms, including potential formation of microcracks during hardening, are essential steps to ensure the quality of cement-based composites and to guarantee their long lifetime. The processes that occur at this early age significantly influence the resulting properties of cement-based composites. Various methods used today to expand the understanding of early hydration include, for example, non-contact complex resistivity, thermogravimetric X-ray computed tomography, scanning electron microscopy, ultrasound or the acoustic emission method. The paper deals with the use of the acoustic emission method to describe the behaviour of cement-based composites during the first 48 hours after mixing cement with water. The acoustic emission sensors allow the detection of elastic waves which may occur during the formation of hydration products, water cavitation, or during the formation and spreading of microcracks (e.g. as a result of plastic shrinkage). The acoustic emission method allows continuous monitoring of the hydration process throughout the experiment and by using the acoustic emission method, there is no need to stop the hydration process to allow its monitoring.

Monitoring of properties of cement-based composites at an early age (approximately during the first 48 hours after mixing cement with water), understanding the hydration processes of the cement paste, and identifying various mechanisms, including potential formation of microcracks during hardening, are essential steps to ensure the quality of cement-based composites and to guarantee their long lifetime. The processes that occur at this early age significantly influence the resulting properties of cement-based composites. Various methods used today to expand the understanding of early hydration include, for example, non-contact complex resistivity, thermogravimetric X-ray computed tomography, scanning electron microscopy, ultrasound or the acoustic emission method. The paper deals with the use of the acoustic emission method to describe the behaviour of cement-based composites during the first 48 hours after mixing cement with water. The acoustic emission sensors allow the detection of elastic waves which may occur during the formation of hydration products, water cavitation, or during the formation and spreading of microcracks (e.g. as a result of plastic shrinkage). The acoustic emission method allows continuous monitoring of the hydration process throughout the experiment and by using the acoustic emission method, there is no need to stop the hydration process to allow its monitoring.

acoustic emission method;cement-based composites;crack;shrinkage;hydration

acoustic emission method;cement-based composites;crack;shrinkage;hydration

HODULÁKOVÁ, M.; TOPOLÁŘ, L.; KUCHARCZYKOVÁ, B.; KOCÁB, D.

2019

23.10.2018

RILEM publications S.A.R.L.

Funchal, Madeira, Portugalsko

978-2-35158-211-4

SynerCrete’18: Interdisciplinary Approaches for Cement-based Materials and Structural Concrete: Synergizing Expertise and Bridging Scales of Space and Time

351

356

6

http://hdl.handle.net/