Sutter, L.
and Bentz, D.
(2017),
Assessing Ash Quality and Performance, Coal Combustion By-products: Characteristics, Utilization, and Beneficiation, Elsevier, London, -1, [online], https://doi.org/10.1016/B978-0-08-100945-1.00009-5 (Accessed May 10, 2026)
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Assessing Ash Quality and Performance
Published
Author(s)
Larry Sutter,
Abstract
This chapter reviews ash quality and performance issues, with special emphasis on air entrainment and early-age performance. Recent developments in testing procedures are reviewed and recommendations are provided for standardized testing. One of the key contributors to variable air contents in concrete mixtures with fly ash is the presence of unburnt carbon. Here, a variety of techniques for assessing the absorption of air-entraining admixtures by the fly ash are presented and critiqued. A second performance issue encountered with fly ash mixtures, particularly high volume fly ash concretes, is early-age retardation that leads to delayed setting and reduced early-age strengths. Isothermal calorimetry is shown to be a valuable troubleshooting technique for evaluating the severity of this retardation. Various mitigation strategies are presented for restoring setting times and increasing early-age strengths to duplicate the performance of 100 % portland cement reference concretes. Finally, the contributions of fly ash to strength development via both pozzolanic and filler effects are assessed using both the standardized strength activity index test and the Keil hydraulic index test. The shortcomings of the former and the promising possibilities of the latter are discussed in detail.Citation
Coal Combustion By-products: Characteristics, Utilization, and Beneficiation
Publisher Info
Elsevier, London, -1
Pub Type
Book Chapters
Download Paper
Keywords
Keywords: Air entrainment, admixture adsorption, incompatibility, isothermal calorimetry, Keil Hydraulic Index test, setting, Strength Activity Index.
Citation
Issues
If you have any questions about this publication or are having problems accessing it, please contact [email protected].
Created May 2, 2017, Updated October 12, 2021