Effect of fly ash microsphere on the rheological properties of alkali-activated fly ash/slag pastes

Author(s): T. Yang, Z. Zhang, X. Gao, H. Zhu
Paper category: Proceedings
Book title:4th International Symposium on Design, Performance and Use of Self-Consolidating Concrete
Editor(s): Caijun Shi & Zuhua Zhang, Hunan University, China
Kamal Henri Khayat, Hunan University, China
Missouri University of Science & Technology, USA
ISBN:978-2-35158-204-6
e-ISBN:978-2-35158-205-3
Publisher: RILEM Publications SARL
Publication year:2018
Pages:151-169
Total Pages:19
Language : English

Abstract: The highly viscous property of alkali silicate-activated cements is one of the critical challenges that hinder their wide application. The present study focuses on ameliorating the rheological performance of sodium silicate-activated fly ash/slag pastes by using fly ash microsphere (FAM), which are highly spherical particles collected from fly ash with electrostatic adsorption classification technology. The FAM particles work as ‘ball-bearings’ in the pastes to reduce the internal friction between fly ash and slag grains, and meanwhile mitigate the agglomeration of flocs and fragmentation to release the locked water. The interrelationship between the FAM particle geometry and plastic viscosity of the paste is well described by the Krieger-Dougherty equation, which supports the proposed mechanisms of ‘ball-bearings’ effects. FAM can work as an inorganic dispersing agent to improve the workability of alkali-activated cement products for a variety of application aspects.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00