Journal Published Online: 09 August 2022
Volume 11, Issue 2

Reactivity of Unconventional Fly Ashes, SCMs, and Fillers: Effects of Sulfates, Carbonates, and Temperature

CODEN: ACEMF9

Abstract

Reactivity information for a range of unconventional fly ashes is unavailable in literature. The objective of this study is to quantify the reactivity of numerous unconventional fly ashes using the R3 test (ASTM C1897-20, Standard Test Methods for Measuring the Reactivity of Supplementary Cementitious Materials by Isothermal Calorimetry and Bound Water Measurements) and the modified R3 test and to determine how sulfates, carbonates, and temperature affect the measured reactivity. A small set of other supplementary cementitious materials and fillers was used to benchmark the fly ash results. Heat release, calcium hydroxide consumption, and bound water were measured for the different materials. For siliceous materials with relatively low calcium oxide (CaO) + aluminum oxide (Al2O3) contents, temperature had a dominant effect on the heat release. On the other hand, for materials with higher CaO + Al2O3 contents, the effects of sulfates and carbonates dominated the effect of temperature. The slow but sustained reactivity of Class F fly ashes highlighted the importance of kinetic corrections or extrapolations to the reactivity measured in the R3 test. However, when testing at 50°C, the heat release curves of all tested materials plateaued at the end of 10 days, indicating that kinetic corrections were not required. Correlations between reactivity and early- and later-age paste properties are discussed.

Author Information

Wang, Ying
Department of Civil and Architectural Engineering, University of Miami, Coral Gables, FL, USA
Ramanathan, Sivakumar
Department of Civil and Construction Engineering, Oregon State University, Corvallis, OR, USA
Burris, Lisa
Department of Civil, Environmental, and Geodetic Engineering, Ohio State University, Columbus, OH, USA
Hooton, R. Douglas
Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON, Canada
Shearer, Christopher R.
Department of Civil and Environmental Engineering, South Dakota School of Mines & Technology, Rapid City, SD, USA
Suraneni, Prannoy
Department of Civil and Architectural Engineering, University of Miami, Coral Gables, FL, USA
Pages: 19
Price: $25.00
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Stock #: ACEM20220003
ISSN: 2379-1357
DOI: 10.1520/ACEM20220003