Understanding expansion in calcium sulfoaluminate–belite cements

Abstract Calcium sulfoaluminate–belite (CSAB) cements are promoted as sustainable alternatives to portland cement because of their lower energy and CO 2 emissions during production and comparable performance. However, the formation of ettringite, the main hydration product in CSAB cements, can be expansive, sometimes resulting in cracking. The factors controlling expansive behavior in CSAB cements have not been completely elucidated. In this study, three CSAB cements synthesized from reagent-grade chemicals with varied phase compositions were examined for dimensional stability in water and sulfate solutions. The interdependent effects of C 4 A 3 Ŝ (Ye'elimite) content, calcium sulfate content, water-to-cement ratio, and particle fineness on CSAB cement expansion were evaluated. The results show that the expansive behavior can be controlled by altering chemical and physical factors in CSAB clinker, cement, and paste.

[1]  Paul E. Stutzman,et al.  Scanning electron microscopy imaging of hydraulic cement microstructure , 2004 .

[2]  F. Glasser,et al.  High-performance cement matrices based on calcium sulfoaluminate–belite compositions , 2001 .

[3]  Deng Min,et al.  Formation and expansion of ettringite crystals , 1994 .

[4]  I. Janotka,et al.  PERFORMANCE OF SULPHOALUMINATE-BELITE CEMENT WITH HIGH C4A3S CONTENT , 2007 .

[5]  K. Snyder,et al.  Sulfate Resistance of Concrete: A New Approach , 2006 .

[6]  P. K. Mehta.  Mechanism of expansion associated with ettringite formation , 1973 .

[7]  E. Gartner.  Industrially interesting approaches to “low-CO2” cements ☆ , 2004 .

[8]  P. Stutzman,et al.  Phase composition analysis of the NIST reference clinkers by optical microscopy and X-ray powder diffraction , 2002 .

[9]  C. W. Richards,et al.  Effects of the particle sizes of expansive clinker on strength-expansion characteristics of type K expansive cements , 1982 .

[10]  Milena Marroccoli,et al.  The influence of C4A3S̄ content and ratio on the performance of calcium sulfoaluminate-based cements , 1996 .

[11]  P. K. Mehta,et al.  Concrete: Microstructure, Properties, and Materials , 2005 .

[12]  Keith Quillin,et al.  Performance of belite–sulfoaluminate cements , 2001 .

[13]  C. Alexandridou,et al.  A study on the hydration products of a non-expansive sulfoaluminate cement , 1995 .

[14]  W. Kurdowski,et al.  On the role of free calcium oxide in expansive cements , 1981 .

[15]  I. Odler,et al.  Investigations on cement expansion associated with ettringite formation , 1999 .

[16]  D. Roy,et al.  C4A3S̄ hydration, ettringite formation, and its expansion mechanism: III. Effect of CaO, NaOH and NaCl; conclusions , 1982 .

[17]  L. Santoro,et al.  Long-term behaviour of hydraulic binders based on calcium sulfoaluminate and calcium sulfosilicate , 1995 .

[18]  Jan Olek,et al.  Mechanism of sulfate attack: A fresh look: Part 1: Summary of experimental results , 2002 .

[19]  Jan Skalny,et al.  Alkalies in cement: A review: II. Effects of alkalies on hydration and performance of Portland cement , 1978 .

[20]  M. Juenger,et al.  Synthesis and hydration of calcium sulfoaluminate-belite cements with varied phase compositions , 2011 .

[21]  Graziella Bernardo,et al.  A porosimetric study of calcium sulfoaluminate cement pastes cured at early ages , 2006 .