Effect of Curing Regime on the Properties of Alkali-Activated Slag/Limestone Mortar Subjected to High Temperatures

Abstract:

Alkali-activated slag has a higher resistance against exposure to high temperature compared to ordinary Portland cement concrete. Nevertheless, its mechanical properties are also deteriorated due to partial decomposition of the C-A-S-H matrix. This paper investigates the effect of various curing regimes applied to the samples which were exposed to temperature 200–1200 °C on the mechanical properties and microstructure of the alkali-activated slag/limestone blends. The amount of limestone was 15% from the mass of slag. On set of specimens was treated on air at laboratory conditions, the second set was immersed in water and the last was treated stored in humid chamber with 95% relative humidity for the period of 60 days. The results showed that water curing has a strong positive influence on the compressive as well as flexural strength of the specimens exposed to temperatures up to 600 °C. Specimens which were exposed to 800 and 1000 °C showed the best performance after treatment in humid chamber, and after exposure to 1200 °C the best compressive strength exhibited the air cured samples.

• Periodical: Materials Science Forum (Volume 865)
• Pages: 37-41
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.865.37
• Online since: August 2016
• Authors: Barbora Fialová*, Pavel Rovnaník
• Keywords: Alkali-Activation, Curing, High Temperature, Limestone, Mechanical Properties, Microstructure, Slag

References

[1] M. Guerrieri, J.G. Sanjayan, F. Collins: Fire Mater. Vol. 33 (2009), p.51.

[2] P. Rovnaník, P. Bayer, P. Rovnaníková: Constr. Build. Mat. Vol. 47 (2013), p.1479.

[3] R. Zhao, J.G. Sanjayan: Mag. Concr. Res. Vol. 63 (2011), p.163.

[4] L. Zuda, P. Rovnaník, P. Bayer, R. Černý: Int. J. Thermophys. Vol. 29 (2008), p.693.

[5] P.C. Hewlitt: Lea's Chemistry of Cement and Concrete (4. ed., Butterworth-Heinemann, USA, 2001).