Abstract
The purpose of this study was to clarify the inhibitory effect of impregnating mortar with an aqueous solution of hydrogen peroxide enriched with aluminum dihydrogen phosphate (HPS) on the alkali-silica reaction (ASR). The expansion over three years of mortar processed using HPS was measured and the outermost surface of the aggregate was analyzed by X-ray photoelectron spectroscopy (XPS). The results obtained were as follows: (1) Compared with the non-soaked aggregate, the outermost surface (1 to 5 nm depth) of HPS-soaked reactive aggregate was improved with silica featuring a more stable Si-O bond as the result of an increase in the amount of active oxygen content; (2) The expansion of the mortar containing HPS-soaked reactive aggregate was significantly smaller than that of mortar containing non-soaked aggregate after 3 years, as determined using the JIS mortar bar method; (3) The expansion of the HPS-impregnated mortar containing reactive aggregate over the 3-year period following 7 days of moist curing tended to be smaller than that of the lithium nitrite aqueous solution (L) impregnated mortar and non-impregnated mortar. From these results, HPS was recognized to be effective in inhibiting the alkali-silica reaction for long periods.
