Title : QUANTITATIVE ANALYSIS OF CHLORIDE ION ABSORPTION CAPABILITY OF ION - EXCHANGE RESIN MIXED IN MORTAR
Authors : Atsushi Sumita, Hiroshi Mutsuyoshi, Yao Luan and Osamu Sanada
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Price : 250
Abstract : Nowadays, the deterioration of concrete due to chloride penetration and reinforcement corrosion has become an important issue affecting safety and durability of structures. To alleviate the process of chloride penetration, the authors have developed a new material by mixing ion-exchange resin (IER) into cement mortar. IER is capable of absorbing chloride ions, and thus decreases the amount of free chloride ions in mortar. In the study, to separate IER from cement mortar, and quantify the amounts of chloride ions absorbed by IER, centrifugation experiment approach is performed. After immersion test in NaCl solution, IER mixed mortar was crushed and grinded into powders, and then sieved through fine mesh. The obtained fine powders were stirred into chloroform which has a specific gravity in between those of mortar and IER. Then, centrifugation was conducted to separate IER powders and mortar powders in the chloroform. The separated IER was filtered on a glass fiber filter and dried in a desiccator. Then, desorption of chloride ions and other anions from IER was performed. After that, the amount of all anions was quantitatively analyzed using capillary electrophoresis, and the amount of chloride ions was quantitatively analyzed using potentiometric titration against silver nitrate. The analytical result shows that a primary portion of ions absorbed by IER are chloride ions, while only little amount are sulfate ions. Therefore, it is confirmed that IER can effectively absorb chloride ions from deteriorated concrete structures. The application of such mortars in rehabilitation engineering is being promoted.