Effects of slag characteristics on sulfate durability of Portland cement-slag blended systems. (30th December 2019)

• Record Type: Journal Article
• Authors: Nosouhian, Farzaneh; Fincan, Mustafa; Shanahan, Natallia; Stetsko, Yuri P.; Riding, Kyle A.; Zayed, A.
• Is Part Of: Construction & building materials. Volume 229(2019)
• Publication Date: 2019-12-30
• Subjects: Ground granulated blast-furnace slag -- Sodium sulfate -- Sulfate resistance -- Thermodynamic modelling; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.116882
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Sulfate durability of GGBFS generally decreased with increasing its Al2 O3 content. Sulfate durability of GGBFS improved with increasing MgO/Al2 O3 ratio of slag. Solid volume increase of hydration products is linearly related to MgO/Al2 O3 ratio. Solid volume increase appears to be related to the length of the induction period. Increasing slag fineness appears to decrease slag sulfate resistance. Abstract: Sulfate resistance of Portland cement-slag mixtures was compared at 30, 50 and 70% cement replacement levels for slags with variable Al2 O3 and MgO content and variable fineness in combination with moderate- and high-C3 A cements. Sulfate resistance generally decreased with increasing slag Al2 O3 content, although decreasing MgO also increased deterioration, particularly at 30% replacement. Increase in Al2 O3 correlated with increased formation of secondary ettringite in the surface of the bars. A linear relationship was observed between the solid volume increase on exposure to sulfate solution predicted by GEMS and the MgO/Al2 O3 ratio of slag at all cement replacement levels. There was also a linear relationship between the solid volume increase and the length of the induction period for the mortar bars exposed to sulfate solution.