Thermal Properties of Alkali-activated Slag Subjected to High Temperatures

Abstract

Alkali-activated slag belongs to prospective materials in the field of fire protection because it exhibits remarkable high-temperature resistance. In this article, specific heat capacity, thermal diffusivity, and thermal conductivity of an alkali-activated slag with sand aggregates are studied as functions of temperature up to 1200^°C. The experiments are performed during the material exposure to high temperatures. The irregularities observed on the measured dependences of specific heat capacity and thermal diffusivity on temperature are discussed using the results of DTA and X-ray diffraction analyses. The crystallization of akermanite is identified as the most important factor affecting the properties of the studied material in high-temperature range.

Keywords

aluminosilicates specific heat capacity thermal diffusivity thermal conductivity high temperatures.

Get full access to this article

View all access options for this article.

References

Byfors, K. , Klingstedt, G. , Lehtonen, V. , Pyy, H. and Romben, L. (1989). Durability of Concrete Made with Alkali Activated Slag, In: Proceedings of the 3rd Int. Conf. on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete, ACISP 114—70 , pp. 1429—1468.

Černý, R. , Toman, J. and Šesták, J. (1996). Measuring the Effective Specific Heat of Building Materials, Thermochimica Acta, 282/283: 239—250.

Davidovits, J. (1999). Chemistry of Geopolymeric Systems. Terminology , In: Davidovits, J., Davidovits, R. and James, C. (eds), Proc. of the Int. Conf. on Geopolymers, Saint-Quentin, pp. 9—39.

Douglas, E. , Bilodeau, A. and Malhotra, V.M. (1992). Properties and Durability of Alkali-Activated Slag Concrete, ACI Materials Journal, 89(5): 509—516.

Downes, R.T. and Hall-Wallace, M. (2003). The American Mineralogist Crystal Structure Database, American Mineralogist, 88(1): 247—250.

Drchalová, J. and Černý, R. (1998). Non-Steady-State Methods for Determining the Moisture Diffusivity of Porous Materials, Int. Comm. Heat and Mass Transfer, 25(1): 109—116.

Merlini, M. , Gemmi, M. and Artioli, G. (2005). Thermal Expansion and Phase Transitions in Akermanite and Gehlenite, Physics and Chemistry of Minerals, 32(3): 189—196.

Robins, P.J. , Austin, S.A. and Issaad, A. (1992). Suitability of GGBFS as a Cement Replacement for Concrete in Hot Arid Climates, Materials and Structures, 25(10): 598—612.

Roels, S. , Carmeliet, J. , Hens, H. , Adan, O. , Brocken, H. , Černý, R. , Pavlík, Z. , Hall, C. , Kumaran, K. , Pel, L. and Plagge, R. (2004). Interlaboratory Comparison of Hygric Properties of Porous Building Materials, Journal of Thermal Envelope and Building Science, 27(4): 307—325.

10.

Rovnaníková, P. and Bayer P. (2001). Korozní odolnost kompozitů na bázi alkalicky aktivované strusky (Corrosion Resistance of Composites on the Basis of Alkali Activated Slag), In: Drochytka, R. (ed.), Proceedings of Int. Conf. CONSTRUMAT 2001, Brno, pp. 49—55.

11.

Shoaib, M.M. , Ahmed, S.A. and Balaha, M.M. (2001). Effect of Fire and Cooling Mode on the Properties of Slag Mortars, Cement and Concrete Research, 31(11): 1533—1538.

12.

Toman, J. and Černý, R. (1993). High-Temperature Measurement of the Specific Heat of Building Materials, High Temp.- High Press., 25(1): 643—647.

13.

Wang, S.D. , Pu, X.C. , Scrivener, K.L. and Pratt, P.L. (1995). Alkali-activated Slag Cement and Concrete: A Review of Properties and Problems, Advances in Cement Research, 27(7): 93—102.