1126. セメント硬化体の溶解に伴う変質(I)

遠心力法によるセメント硬化体の通水試験

抄録

Many studies to clarify the mechanism, which hydrated cement maintains high pH condition for a long period have been reported. However, due to the lack of solid phase analysis, they do not related to the dissolution process of cement hydrates. We have performed a permeability test in which centrifugal force is used to percolate pore water and have studied the change of aqueous chemistries and that of the solid phase simultaneously in order to investigate the dissolution phenomena of hydrated cement.
The dissolution process of the hydrate phase agreed with that of the results of the other dissolution tests that is dissolving in the order of Na₂O and K₂O, Ca(OH)₂ and C-S-H gel. Accordingly, it was ascertained that this permeability test was carried out under the equilibrium condition between percolated pore water and hydrates. It was confirmed that pore volume increased by the dissolving of hydrates and pore structure clearly changed. The relation between the volume of percolated water and its chemical composition was evaluated by the model coupling transport and chemical equilibrium calculations. The calculated calcium and silicon concentrations of the percolated water were in good agreement with the experimental values, and thus, we were considered that this model was useful for evaluating the behavior of cement hydrates dissolution.