Study on Controlling Effect of Alkali-Silica Reaction by Impregnation Using Aqueous Solutions of Hydrogen Peroxide
Kazuo SEKINO and Naomitsu TSUYUKI
Abstract:The purpose of this study is to grasp of controlling effect of alkali-silica reaction (ASR) by impregnation using hydrogen peroxide 5% aqueous solution (H5), hydrogen peroxide 5% with aluminium dihydrogenphosphate 3% aqueous solution (H5AP3) and lithium nitrite aqueous solution(L) as to impregnant. In this study, the expansion and compressive strength of impregnated and non-impregnated mortars were discussed. The mortars used for impregnation were subjected to various pre-curing conditions. The reactive aggregates used in the mortars were trachyte, glass cullet and andesite.The results obtained are as follows : (1) The reduction of ASR-expansion in the H5-impregnated mortars was influenced by total alkali content, pre-curing condition, impregnant loading and moist curing period of the mortar. (2) The expansion of the impregnant(H5, H5AP3 and L)-impregnated mortars was remarkably smaller than that of the non-impregnated mortar at moist curing eriod from 7 days to 3 years. Especially, the expansion of the H5AP3-impregnated mortar was decreased, as compared with L. (3) The compressive strength of the impregnant(H5,H5AP3 and L)-impregnated mortars was larger than that of the non-impregnated mortar at moist curing period of 3 years. Especially, the compressive strength by impregnation with H5AP3 was increased, as compared with L. (4) From these results, it was recognized that H5AP3 as to impregnant was possessed with controlling effect of ASR and high compressive strength developments, as compared with L. Key Words:Alkali-silica reaction, Hydrogen peroxide, Aluminium dihydrogenphosphate, Lithium nitrite, Impregnant, Expansion, Compressive strength