A starch-based admixture for reduction of hydration heat in cement composites. (10th June 2018)

• Record Type: Journal Article
• Authors: Zhang, Hao; Wang, Wenbin; Li, Quanlong; Tian, Qian; Li, Lei; Liu, Jiaping
• Is Part Of: Construction & building materials. Volume 173(2018)
• Page Start: 317
• Page End: 322
• Publication Date: 2018-06-10
• Subjects: Temperature -- Hydration; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.03.199
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A starch-based admixture (SA) used to modify the cement hydration heat process was reported. Temperature variation of mortar and effects of starch-based admixture on setting time and strength were assessed experimentally. The evolution of the hydration process and micro-structure of cement paste with SA was monitored to reveal the mechanism. Abstract: In this paper, the effect of a new starch-based chemical admixture (SA) on cement hydration is investigated and its preliminary action mechanism is discussed. The results from isothermal calorimeter and semi-adiabatic calorimetry test show that SA could decrease the maximum heat flow from the 2.6 mW/g to 1.5 mW/g and the peak temperature from 35.9 °C to 24.9 °C when the SA dosage increased from 0% to 0.6% (weight ratio of SA/cement). The effect of SA with different dosage on cement hydration has also been investigated by electrical resistance test and X-ray diffraction analysis. Though the cement hydration rate is decreased at early stage, it has no influence on the final total heat release and no influence on concrete compress strength at 28 d. Such results show that it might have great sense to control thermal crack in mass concrete in practical application which is normal problem in mass concrete.