Effect of temperature on the chloride binding capacity of cementitious materials

Abstract

The effect of temperature on the chloride binding capacity (CBC) of cementitious materials was investigated. A reactive transport model including thermodynamic equilibrium, kinetic control and surface complexation was applied to investigate this effect. The surface complexation model was completed by introduction of the equilibrium constant of calcium silicate hydrate (C–S–H) complexation reactions at different temperatures (5, 21 and 35°C). In order to validate the developed numerical model, the results were compared with experimental data obtained from the literature. Good agreement was found between the numerical and experimental CBCs. The effect of temperature on the CBC of cementitious materials was evaluated and is discussed in this paper. The van 't Hoff equation of C–S–H surface complexation reactions (SCRs) and variation of the standard thermodynamic properties of the SCR (Δ r H T0 (kJ/K) and Δ r S T 0 0 ) at the reference temperature of T 0 = 25°C and p 0 = 1·1013 × 10 5 Pa are also presented.