Simultaneous effect of silica fume, metakaolin and ground granulated blast-furnace slag on the hydration of multicomponent cementitious binders
Portland cement was partially replaced by metakaolin (MK), silica fume (SF) and ground granulated blast-furnace slag (BFS). Globally, two amounts of SF (5 and 10 mass%) and total substitution level of 35 mass% were used to prepare blended samples. Their early and 28 days hydration was studied by means of isothermal calorimetry and thermal analysis. Developed phase composition was assessed using compressive strength measurements. Acceleration of cement hydration in early times was proved and reflected higher amounts of finer additives. Despite dilution effect, the presence of more reactive SF and MK resulted in pozzolanic reactions manifesting already before 2 days of curing and contributing to the formation of strength possessing phases. The influence of BFS addition showed later and thanks to the synergic effect of all the used additives; it was possible to increase its content up to 25 mass% by keeping the compressive strength values near that of referential one.
KeywordsMulticomponent cements Metakaolin Silica fume Ground granulated blast-furnace slag Isothermal calorimetry Thermal analyses
This work was supported by courtesy of APVV-15-0631, Slovak Grant Agency VEGA No. 2/0097/17 and by Project Sustainability and Development REG LO1211 addressed to the Materials Research Centre at FCH VUT.
- 11.EN 197-1. Cement. Part 1: Composition, specifications and conformity criteria for common cements. 2011.Google Scholar
- 12.EN 196-1. Methods of testing cement. Part 1: determination of strength. 2016.Google Scholar
- 14.Taylor HFW. Cement chemistry. 2nd ed. London: Thomas Telford; 1998.Google Scholar
- 19.Zelić J. Study of effect of amorphous silica on early stages of hydration and on stability of cement stone. In: PhD Thesis, University of Split, Split; 1997.Google Scholar
- 21.Skalny JP, Young JF. Mechanisms of Portland cement hydration. In: The 7th international congress of the chemistry of cement, Paris, II-1/3–II-1/45; 1980.Google Scholar
- 22.Wu ZQ, Young JF. Formation of calcium hydroxide from aqueous suspensions of tricalcium silicate. J Am Ceram Soc. 1984. https://doi.org/10.1111/j.1151-2916.1984.tb19146.x.Google Scholar
- 25.Ibrahim IA, ElSersy HH, Abadir MF. The use of thermal analysis in the approximate determination of the cement content in concrete. J Therm Anal Calorim. 2004. https://doi.org/10.1023/b:jtan.0000032255.58397.4b.Google Scholar
- 30.Kocaba V. Development and evaluation of methods to follow microstructural developments of cementitious systems including slags. In: Ph.D. thesis. École Polytechnique Fédérale de Lausanne; 2010.Google Scholar