A study of the effects of nickel chloride and calcium chloride on hydration of portland cement
β Scribed by H. Akhter; F.K. Cartledge; A. Roy; M.E. Tittlebaum
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 635 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0008-8846
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β¦ Synopsis
Portland cement samples containing amounts of CaCl 2 and NiCl 2 ranging from approximately 1% to 20% by weight have been examined by 29Si and 2~i solid-state MAS NMR as a function of time, and some of the mature pastes have been characterized by X-ray diffraction.
Changes in physical properties that had been previously observed as a function of amounts of salt added are clearly traceable to differences in the silicate matrices.
Low concentrations of both salts promote Ql formation, but high concentrations result in formation of much more Q2 at the expense of Qt. Both salts accelerate both aluminate and silicate hydration, and the effects appear to be almost entirely due to chloride.
Minor variations in hydration rates at high Ni concentrations may be the result of nickel salt precipitation.
π SIMILAR VOLUMES
The effects of CaCl 2, calcium gluconate, mixture of CaCl 2 and calcium gluconate, glucose and mixture of glucose and calcium gluconate on the hydration of three different portland cements have been studied using isothermal microcalorimetry, x-ray diffraction, chemical analysis of the liquid phase a
Two sets of neat paste samples, prepared with an ordinary Portland cement and a ternary blended cement (containing slag and fly ash), were stored in various corrosive solutions of different pH (11.5 and 13) and chloride concentrations (up to 20 g/1 of Cl'). Structural and textural alterations were i
The hydration of portland cement in presence of citric acid has been investigated. The results indicate that O.l% citric acid accelerates whereas too high a dose (> 0.1%) of citric acid retards the hydration. Electrical conductivity measurements of the paste indicate that in the presence of citric a
Conduction calorimetry has been used to study the patterns of early heat evolution during the hydration of Portland cement. In particular, the effect of sulphate on the rate of heat liberation has been investigated with reference to the differences observed depending on whether the sulphate is prese