Characterization of morphology and hydration products of high-volume fly ash paste by monochromatic scanning x-ray micro-diffraction (mu-SXRD)

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Bae S., Meral Ç., Oh J., Moon J., Kunz M., Monteiro P. J.

CEMENT AND CONCRETE RESEARCH, cilt.59, ss.155-164, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 59
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1016/j.cemconres.2014.03.001
  • Dergi Adı: CEMENT AND CONCRETE RESEARCH
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.155-164
  • Anahtar Kelimeler: High-volume fly ash, Microstructure (B), C-S-H(I), Scanning transmission x-ray micro-diffraction, Stratlingite, C-S-H, CALCIUM-SILICATE-HYDRATE, HIGH-ALUMINA CEMENT, MECHANICAL-PROPERTIES, DRYING SHRINKAGE, PORTLAND-CEMENT, STRENGTH, SLAG, MICROSTRUCTURE, AL
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

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 (mu-SXRD) and SEM-EDS. Pastes with up to 80% fly ash replacement were studied. Phase maps for HVFA samples using mu-SXRD patterns prove that mu-SXRD is an effective method to identify and visualize the distribution of phases in the matrix. mu-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(1) with comparatively lower Ca/Si ratio than the one produced in PC system. Moreover, coexistence of C-S-H(1) and stratlingite 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 stratlingite in HVFA system. (C) 2014 Elsevier Ltd. All rights reserved.