アルカリシリカ反応によって劣化したコンクリートの組織と残留膨張性の予測

抄録

Recently, a number of bridge concrete piers which appear to be damaged by the alkali-silica reaction, have been found in a certain district in Japan. The major purpose of this study is to reveal whether the damage in the concrete piers was caused by an alkali-silica reaction. Another important problem is to predict the residual expansion capacity of the affected concretes for the purpose of repairing them appropriately. The reactivity of aggregates used in the concretes was investigated by microscopic examination. In this district, a large amount of sodium chloride is being used as a deicing agent for many years. Accelerated expansion tests in saturated NaCl solution as well as in high humidity were carried out to predict the residual expansion of the actually damaged concrete piers. The correlation between the results obtained by the accelerated expansion tests in saturated NaCl solution and in high humidity was found to be considerably good. Andesitic and rhyolitic aggregates in the concretes were reacting.