Development of Evaluation Method of Alkali-Silica Reactivity of Concrete Using River Sand and Gravel in Hokuriku District
Masahiro NOMURA, Kazuyuki TORII and Minobu AOYAMA
Abstract:The purpose of this paper is to develop an evaluation method for assessing the alkali-silica reactivity of concrete with a combination of the river sand and gravel used in the Hokuriku district. The 27 aggregate samples were collected from the stockpile of selected 8 ready-mixed concrete plants over the main river area in this district. The mineralogical features of the river sand and gravel, and their alkali-silica reactivity were tested by both the chemical method and the mortar bar method according to the specification by JIS A 1145-2001 and JIS A 1146-2001. Furthermore, a lot of cores were drilled from the concrete specimens, which were subjected to the accelerated curing condition of the immersion into 1N NaOH solution at 80 or the saturated NaCl solution at 50 in order to evaluate the alkali-silica reactivity of the concrete itself. By measuring the expansion behaviors of the cores in the accelerated curing condition, the rapid test method for the evaluation of the alkali-silica reactivity of the concrete itself was developed. Key Words:Alkali-silica reaction, Accelerated curing test, Concrete core , Reactive component, Andesite