Estimating the electrical conductivity of cement paste pore solutions from OR-, K+ and Na+ concentrations
نویسندگان
چکیده
A proposed method for estimating the electrical conductivity of cement paste pore solution at 25 °C is based on the concentrations of OR -, K + and Na + .The approach uses an equation that is a function of the solution ionic strength, and requires a single coefficient for each ionic species. To test the method, the conductivity of solutions containing mixtures of potassium hydroxide and sodium hydroxide with molar ratios of4:1, 2:1 and 1:1, and having ionic strengths varying from 0.15 to 2.00 moVI were measured in the laboratory and compared to predicted values. The proposed equation predicts the conductivity of the solutions to within 8% over the concentration range investigated. By comparison, the dilute electrolyte assumption that conducti,'ity is linearly proportional to concentration is in error by 36% at I mol/! and in error by 55% at 2 mol/l. The significance and utility of th,~ proposed equation is discussed in the context of predicting ionic transport in cement-based systems. Published by Elsevier Science Ltd.
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