[KSCI] Korea Science Citation Index Service

http://dx.doi.org/10.5659/AIKAR.2011.13.1.25

Premature Stiffening of Cement Paste Caused by Secondary Gypsum and Syngenite Formation (False Set)

Chung, Chul-Woo (Pacific Northwest National Laboratory)
Lee, Jae-Yong (Department of Architectural Engineering, Pukyong National University)

Publication Information

Architectural research / v.13, no.1, 2011 , pp. 25-32 More about this Journal

Abstract

The purpose of this research is to investigate the effect of specific hydration reaction on the stiffening process of cement paste. The cement compositions are manipulated to cause specific hydration reactions (secondary gypsum and syngenite formation) responsible for false set, and the relationship between specific hydration reactions and the flow and stiffening behavior of cement paste were investigated using modified ASTM C 403 penetration resistance measurement and oscillatory shear rheology. X-ray powder diffraction (XRD) was used for the phase identification associated with premature stiffening of cement paste. Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were used for verification of syngenite formation. From the results, both secondary gypsum and syngenite formation caused faster stiffening and set. The amount of syngenite produced during 1 hour hydration was approximately 1 % of total mass of the cement paste, but cement paste with syngenite formation showed significantly accelerated stiffening behavior compared to normal cement paste.

Keywords

Penetration Resistance; Syngenite Formation; Secondary Gypsum Formation; False Set; Cement Paste;

Citations & Related Records

Reference

1	Channell, G. M., and Zukoski, C. F. (1997), "Shear and Compressive Rheology of Aggregate Alumina Suspensions, AICHE Journal, Vol. 43: 1700-1708. DOI ScienceOn
2	Channell, G. M., Miller, K. T., and Zukoski, C. F. (2000), "Effect of Microstructure on the Compressive Yield Stress, AICHE Journal, Vol. 46: 72-78. DOI ScienceOn
3	Chen, L. B. (1991), "The Dynamic Properties of Concentrated Charge Stabilized Suspensions". Ph.D dissertation, University of Illinois at Urbana-Champaign, Urbana (IL).
4	Chung, C. -W., Mroczek, M., Park, I. -Y., and Struble, L. J. (2010), "On the evaluation of setting time of cement paste based on ASTM C 403 penetration resistance test", Journal of Testing and Evaluation, Vol. 38: 527-533.
5	Lei W. G., and Struble. L. J. (1997), "Microstructure and Flow behavior of Fresh Cement Paste," Journal of American Ceramic Society, Vol. 80: 2021-2028.
6	Mindess, S., Young, J. F., and Darwin, D. (2003), Concrete, 2nd edition, Prentice Hall.
7	Struble, L. J., and Sun, G. - K. (1995), Viscosity of Portland Cement Paste as a Function of Concentration, Advanced Cement Based Materials, Vol. 2: 62-69. DOI ScienceOn
8	Struble, L. J., Kim, T.-Y., and Zhang, H., Setting of Cement and Concrete. Journal of Cement, Concrete, and Aggregate, 2001, Vol. 23:
9	Suzuki, K., Nichikawa, T., Kato, K., Hayashi, H., and Ito, S. (1981) "Approach by Zeta-Potential Measurement on the Surface Charges of Hydrating $C_3S$ ," Cement and Concrete Research, Vol. 11: 759-764. DOI ScienceOn
10	Taylor, H. F. W. (1997), Cement Chemistry, 2nd edition, Academic Press, Thomas Telford edition,
11	Zhang, H. (2001), "Using Dynamic Rheology to Explore the Microstructure and Stiffening of Cementitious Mixtures, Ph.D dissertation, University of Illinois at Urbana Champaign, Urbana (IL).
12	ASTM Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance (C 403), Annual Book of ASTM Standards, Vol. 04. 02, ASTM International, West Conshohocken, PA, 2003.
13	Aitcin, P. C. (1998), High Performance Concrete, E & FN SPON,
14	ASTM Test Method for Time of Setting of Hydraulic Cement by Vicat Needle (C 191), Annual Book of ASTM Standards, Vol. 04. 01, ASTM International, West Conshohocken, PA, 2003.