ALKALI-SILICA REACTIVITY OF ANDESITE IN NACL SATURATED SOLUTION
This paper presents the alkali-silica reactivity of andesite and expansion behaviorof mortar in NaCl saturated solution. Glassy andesite without silica minerals was non-expansive in a NaCl saturated solution,whereas mortar bars using cristobalite-bearingaggregate showed large expansions. Dissolution of glass and cristobalite depend on OH-concentration of alkali solution. OH-concentration of pore solution of mortar under NaClsaturated solution was low. Under this condition dissolved amount of glass is not enough tocause expansion whereas cristobalite dissolved enough. These results indicate one possibilityof limited risk of glassy andesite without reactive silica minerals in specific conditions even ifalkalis are supplied from environments,such as deicing salts or sea salt as long as the initialalkali content in concrete is controlled under certain amount. In NaCl saturated solution,expansion of mortar bars incorporating cristobalite-bearing aggregate was larger althoughOH-concentration of its pore solution was lower. This result may be caused by the incrementin dissolution of cristobalite because of high ionic strength.
andesite Danish test pore solution OH concentration Ionic strength
Takanori Ikeda Yuichiro Kawabata Hidenori Hamada Yasutaka Sagawa
Graduate school of Engineering,Kyushu University,Japan Port and Airport Research Institute,Japan Faculty of Engineering,Kyushu University,Japan
国际会议
The International Conference on Durability of Concrete Structures(2008年混凝土结构耐久性国际学术会议)
杭州
英文
563-569
2008-11-01（万方平台首次上网日期，不代表论文的发表时间）