Influence of Alkali Contents of Cement and Testing Methods on Expansion of Mortar Bars due to Alkali-Silica Reaction
Takeyuki KIMIJIMA, Seiichi NAGAOKA, Kimihiko NAKAYAMA and Shigehiro KOBAYASHI
Abstract:Some problems are pointed out about the examination method of evaluating the alkali reactivity of aggregate. For example, by the mortar bar method of JIS without supply of alkali from the exterior, and the method immersed in the NaOH solution defined by ASTM and the method immersed in saturation NaCl solution (Denmark method), the judgment result changes with kinds of aggregate. Then, in order to acquire broad knowledge about the factor influenced on an examination result in this research, the influence affect the result which alkali content of cement depends on the various examination methods was considered. Consequently, it became clear that the grades influenced alkali content and the kind and the amount of reactant mineral in aggregate by the examination method differ. Especially, a result, which supports indication that it is necessary to examine whether the Denmark method for having an advantage, like that it can judge for a short period of time and a judgment result becomes clear can apply to the aggregate of our country, was brought. Key Words:Alkali reactivity, Alkali content of cement, Examination methods, Denmark method