Impact of four kinds of alkanolamines on hydration of steel slag-blended cementitious materials. (30th January 2017)

• Record Type: Journal Article
• Authors: Yang, Songge; Wang, Jianfeng; Cui, Suping; Liu, Hui; Wang, Xueli
• Is Part Of: Construction & building materials. Volume 131(2017)
• Page Start: 655
• Page End: 666
• Publication Date: 2017-01-30
• Subjects: Steel slag blend cementitious material -- Alkanolamine -- Hydration -- Induction period -- Microstructure; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2016.09.060
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Different types of Alkanolamines were investigated on hydration reactions. The mineral contents of the hydrates were quantitatively analyzed. Different dosages of Alkanolamines were studied in hydration heat experiment. The pore structure and microstructure of hydrates was explored. TEA and DEIPA have better effects on improving the hydration reactions. Abstract: The impact on hydration of four kinds of alkanolamines (triethanolamine (TEA), triisopropanolamine (TIPA), diethanol-isopropanolamine (DEIPA) and methyldiethanolamine (MDEA)) in a steel slag cementitious system was reviewed. Isothermal calorimetry studies provided information on the hydration heat release rate and the cumulative energy released by blend cement systems. Mortar strength, quantitative X-ray diffractometry, mercury intrusion pore size distribution analysis, scanning electron microscopy and thermogravimetric analysis were used to analyze the mechanism of strength enhancement and micro-structure of hydrates that were impacted by alkanolamines. Alkanolamines prolonged the hydrated induction period in the steel slag–cement system, and enhanced the second exothermic peak of hydration at dosages of 0.01%, 0.03% and 0.05%. The second hydration rate was decreased by TEA, DEIPA and MDEA, and increased by TIPA at alkanolamine dosages of 0.1% and 0.2%. The compressive strength and non-evaporable water content were enhanced by the four types of alkanolamines (dosage of 0.03%) at 3 d, 7 d and 28 d, which allowed TEA and DEIPA to contribute to strength development and the hydration reaction over TIPA and MDEA. The CH content, porosity and pore size were decreased by alkanolamines at different ages. Alkanolamines promoted the formation of ettringite and an alumina–ferric oxide–monosulfate phase, and the C–S–H morphology was also changed by different kinds of alkanolamines.