化学物質の少量添加によるアルカリシリカ反応の抑制に関する研究

Abstract

This paper describes effect of restraint of alkali silica reaction (ASR) by adding a small amount of chemical materials. In general, the measures for restraining the ASR are the total alkali content (under 3.0 kg/m3) and the use of mixed cement (blast-furnace slag cement type B or C, fly ash cement B or C). However, it is necessary to use more than a certain quantity (for example: 100 kg/m3). Therefore the development of the materials which can restrain ASR by adding a small amount is expected. In the experiments, mortars were made using ordinary portland cement, restraint materials and 4 types of reactive aggregates (2 types of chert, andesite, slate). Effects of restraint of 3 types of chemical materials were examined. They are the calcium propionate, the lithium-based compound and the aluminum-based compound. As a result, the expansions of mortars were restrained by the addition of the calcium propionate of 1.8 % in cement weight and also were restrained by the addition of the lithium carbonate of 2.5 % in cement weight.