QUANTITATIVE REPRESENTATION OF THE COMBINATION OF CALCIUM CHLORIDE WITH HYDRATING PORTLAND CEMENT AND BLAST FURNACE SLAG IN TERMS OF ION EXCHANGE EQUILIBRIA

Several authors have shown that when tricalcium silicate, portland cement or sulphate-resisting cements undergo hydration in solutions of calcium chloride, the extent to which chloride is bound in the hydration products increases with the concentration of chloride in solution. These trends were confirmed by the writer during an investigation into the effect of calcium chloride on the kinetics of hydration of portland cement and blast-furnace slag. It has been postulated by some authors that the above results pointed to a concentration-dependent chemical equilibrium and by others that the interlayer ion in the lamellar hexagonal calcium aluminate hydrate structure should be regarded as an exchangable anion. Prompted by these hypotheses, the writer concluded that the extent of combination of chloride in hydrated cements could be approached in terms of ion-exchange equilibria. Since the extent to which various compounds are formed during room temperature hydration of cement are not readily measured by x-ray diffraction and infra-red spectrometry, an idealized composition was calculated for each fully-hydrated cement, from which an anion-exchange capacity was computed. The bound chloride contents, chloride concentration and exchange capacities were then related by means of an empirical equation suggested by Walton. In the case of blast-furnace slag and mixtures of portland cement and blast-furnace slag, satisfactory results were obtained. Results for portland cement were, however, less satisfactory, reflecting the uncertainties involved in using idealized compositions of the hydrates. (a). For the covering abstract of the conference, see IRRD abstract no. 213776. /TRRL/

• Supplemental Notes:
  • Presented at the First Australian Conference on Engineering Materials.
• Corporate Authors:

  University of New South Wales

  School of Civil Engineering, Anzac Parade
  Kensington, New South Wales  Australia  2033
• Authors:
  • Wolhuter, C W
• Publication Date: 0

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: 15 p.

Subject/Index Terms

• TRT Terms: Blast furnaces; Calcium chloride; Cement; Chloride content; Concentration (Chemistry); Equations; Hydration; Ion exchange; Portland cement; Slag
• Uncontrolled Terms: Chemical equilibrium
• Old TRIS Terms: Empirical equations; Ion exchange tests
• ITRD Terms: 7315: Calcium chloride; 4758: Cement; 7132: Concentration (chem); 7195: Hydration; 7144: Ion exchange; 4561: Slag
• Subject Areas: Geotechnology; Highways; Materials; Planning and Forecasting; I32: Concrete; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 00129554
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Report/Paper Numbers: Conf Paper
• Files: ITRD, TRIS
• Created Date: May 14 1976 12:00AM