Title: Hydration Properties of Calcium Sulfoaluminate-Portland Cement Blends

Author(s): M. Bianchi, F. Canonico, L. Capelli, M.L. Pace, A. Telesca, and G.L. Valenti

Publication: Symposium Paper

Volume: 261

Issue:

Appears on pages(s): 187-200

Keywords: calcium sulfoaluminate; early hardening; ettringite; expansion; shrinkage compensation.

DOI: 10.14359/51663210

Date: 10/1/2009

Abstract:
The X-ray diffraction analysis and mercury intrusion porosimetry were employed to investigate the hydration process of calcium sulfoaluminate (CSA)- portland cement blends with C4A3S mass concentration, C3S/C4A3S, and CS/C4A3S mass ratios ranging from 7.7 to 22.0%, 1.0 to 6.5, and 0.5 to 1.2, respectively. Owing to the hydration of adequate C4A3S contents and the generation of sufficient quantities of expansive ettringite, blends with C4A3S amounts as well as C3S/C4A3S and CS/C4A3S values comprised between 17.6 and 22.0%, 1.0 and 1.7, 0.5 and 1.0, respectively, showed high-early strengths and low drying-shrinkage when compared to normal portland cements. The formation of expansive ettringite was associated with concentrated pore distributions and most preferred pore radii ranging from either 47 to 225 or 367 to 896 nanometers, depending on both C3S/C4A3S and CS/C4A3S ratios.