Abstract

This research investigates the impact of accelerated carbonation treatment on the pozzolanic reactivity of high-calcium fly ash (HFA) by monitoring the reaction heat of HFA/carbonated HFA (CFA)-calcium hydroxide (CH) blends and elucidates the underlying factors influencing the pozzolanic reactivity. The results indicate that in HFA/CFA-CH blends, CFA exhibits a comparable pozzolanic reactivity to that of HFA. This is attributed to the carbonation products accelerating the formation of MonoCarb aluminate (main) and C-S-H, compensating for the reduced heat resulting from the diminished highly reactive components after the carbonation treatment. Additionally, the increased surface area due to carbonation treatment is favorable for the pozzolanic reaction of CFA. However, in the HFA/CFA-CH blends with gypsum, the carbonation treatment adversely affects the pozzolanic reactivity of HFA since gypsum limits the MonoCarb aluminate formation. Overall, these findings suggest that when proportioned and used properly, CFA can retain comparable pozzolanic reactivity to that of the untreated HFA, while storing CO2 permanently.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

National Science Foundation, Grant 2219086

Keywords and Phrases

Calorimetry; Carbonation; High-calcium fly ash; Hydration products; Pozzolanic reactivity

International Standard Serial Number (ISSN)

0950-0618

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Elsevier, All rights reserved.

Publication Date

04 Oct 2024

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