Characterization of morphology and hydration products of high-volume fly ash paste by monochromatic scanning x-ray micro-diffraction (μ-SXRD)
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of)
- Civil Engineering Program, Department of Mechanical Engineering, State University of New York at Stony Brook, NY 11794 (United States)
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)
The present study focuses on identification and micro-structural characterization of the hydration products formed in high-volume fly ash (HVFA)/portland cement (PC) systems using monochromatic scanning x-ray micro-diffraction (μ-SXRD) and SEM-EDS. Pastes with up to 80% fly ash replacement were studied. Phase maps for HVFA samples using μ-SXRD patterns prove that μ-SXRD is an effective method to identify and visualize the distribution of phases in the matrix. μ-SXRD and SEM-EDS analysis shows that the C-S-H formed in HVFA system containing 50% or more of fly ash has a similar structure as C-S-H(I) with comparatively lower Ca/Si ratio than the one produced in PC system. Moreover, coexistence of C-S-H(I) and strätlingite is observed in the system containing 80% of fly ash, confirming that the amount of alumina and silicate phases provided by the fly ash is a major factor for the formation of C-S-H(I) and strätlingite in HVFA system. - Highlights: • High-volume fly ash (HVFA) paste was studied by scanning x-ray micro-diffraction. • Coexistence of C-S-H(I) and strätlingite in the HVFA system is clearly shown. • The distribution of minor phases in the HVFA system is shown. • Differences between inner and outer products of fly ash are observed by SEM-EDS.
- OSTI ID:
- 22323142
- Journal Information:
- Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 59; ISSN 0008-8846; ISSN CCNRAI
- Country of Publication:
- United States
- Language:
- English
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