CHLORIDE BINDING ISOTHERMS IN CONCRETE: THE EFFECT OF AGGREGATES AND ADMIXTURES

Chloride binding isotherms of several cement-based materials are determined in the paper taking into account the presence of aggregates and admixtures. The experiments are performed on small but not crushed specimens so that the effect of the porous structure is respected. Also, the experiment with crushed samples as in the original adsorption procedure by Tang and Nilsson is done for the sake of comparison. The experimental results show that the chloride binding capacity of cement-based materials depends significantly on the size of the sample. Therefore, the current practice with using crushed specimens does not seem to be realistic. Also, the recalculation of the chloride binding isotherms to the amount of cement in the specimen in order to achieve a possible extension of the measured results to other cementbased materials does not seem to be a reasonable solution. The recalculation with respect to the interior pore surface of a material might be a better option.

• INTRODUCTION

• EXPERIMENTAL METHODS FOR MEASURING CHLORIDE-BINDING ISOTHERMS

• MATERIALS AND SAMPLES

• EXPERIMENTAL METHODS

• RESULTS AND DISCUSSION

• CONCLUSIONS

• ACKNOWLEDGEMENTS

• REFERENCES