Abstract
The quality of shotcrete is lower than that of cast-in-place concrete because of its materials used and its construction process. Objectives of this study are to improve several properties of shotcrete and to enable us to manufacture high-quality shotcrete. The results obtained within the scope of this study may be summarized as follows :High-quality shotcrete can be economically manufactured by using a water reducing agent, not increasing unit water content, because a dosage of a set accelerating agent can be decreased. Compressive strength and the resistance to carbonation of shotcrete can be improved by using a set accelerating agent whose principal ingredient is calcium sulfoaluminate. The resistance to freezing and thawing of shotcrete can also be improved by incorporating plastic hollow microspheres that act as an air entraining agent, however the shotcrete does not necessarily possess sufficient durability due to the existence of large pores like honeycomb induced by shotcreting.
