Abstract
In the construction of Higashi Shimizu Substation, artificial bedrock were first built using a concrete containing a high volume of fly ash. This paper describes the preliminary examination of the replacement ratio of fly ash and the quality control of fly ash concrete. As a result, fly ash concrete could prove that it was meeting a design condition and that the compressive strength dispersion showed normal distribution. It could be confirmed that fly ash concrete had enough quality, and that it is possible to control quality like ordinary concrete.