The effect of elevated temperature on the residual tensile strength and physical properties of the alkali-activated slag concrete. (November 2018)

• Record Type: Journal Article
• Authors: Behfarnia, Kiachehr; Shahbaz, Mohammad
• Is Part Of: Journal of building engineering. Volume 20(2018)
• Page Start: 442
• Page End: 454
• Publication Date: 2018-11
• Subjects: Alkali-activated -- Concrete -- Slag -- Tensile strength -- Mass loss; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2018.08.015
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: Assessment of alkali-activated slag (AAS) concrete as a green alternative to normal concrete is an effort to pave the way for the sustainable development. In this study, the AAS concrete specimens, after 7, 28 and 90 days of wet curing, were exposed to the temperatures of 20, 200, 400, 600, and 800 °C, and the effect of temperature on their residual tensile strength and mass loss was assessed. Specimens of the normal concrete were also cast and tested to compare their performance with that of the AAS concrete. According to the results, the residual tensile strength of the AAS concrete at high temperatures was noticeably higher than that of normal concrete. Scanning electron microscope (SEM) images were obtained from the specimens to observe the changes in the micro-structure of the AAS and normal concrete in response to heating. Also, the change in the structure of the pores of the AAS concrete was investigated by employing mercury intrusion porosimetry (MIP). Highlights: Mass reduction in the AAS concrete was lower than that of the normal concrete. The tensile strength of the concrete specimens was decreased as the temperature was increased. As the temperature was raised, the number and size of the pores in the AAS concrete were increased. Residual tensile strength of the AAS concrete was remarkably higher than that of the normal concrete.