Properties of shotcrete with highly functional fly ash used as dust-reducing agent K. Sasaki, M. Ishii & Y. Butou Coal Ash Recycle Project Group, Shikoku Electric Power Co., Inc., Japan K. Yuno Yonden Business Co., Inc., Japan ABSTRACT: Shikoku Electric Power Co., Inc., has developed the technology to manufacture a brand name “FINASH” about 10 years ago, by sorting and classifying coal ash generated in coal fired power plants. “FINASH” is highly functional fly ash which is produced by removing irregular coarse particles, a key factor causing variation in quality of coal ash, with sophisticated classification technique and extracting good quality spherical fine particles. It is now utilized as concrete admixture for civil engineering structures and buildings. The concrete with highly functional fly ash has some advantages of enhancing long-term strength development and improving durability and workability. Thus, it has been used in many construction works executed by Ministry of Land, Infrastructure and Transport and West Nippon Expressway Company Limited（the old Japan Highway Public Corp）and so on. In this paper, properties (workability, strength development and durability) of concrete with highly functional fly ash used as dust-reducing agent are described.