覆工としての吹付けコンクリートの強度特性と耐久性に関する研究
1988 年 1988 巻 391 号 p. 46-55
詳細
1988 年 1988 巻 391 号 p. 46-55
In recent years, the shotcrete has been increasingly applied to a permanent concrete lining of a tunnel. However, the durability of shotcrete is not yet established because of temporary structure. This paper investigates the influences of the factors involved in shotcrete such as the execution intervals between the shot layers, the kind of accelerators and addition of dust-reduer, upon its strength and durability characteristics particularly upon the resistance to freezing and thawing, by doing experiments and a statistical analysis. From the results of these investi gations, the following conclusions have been drawn: (1) The kind of accelerators have large influence on the quality of shotcrete. (2) Addition of dust-reducer increases resistance to freezing and thawing on account of tiny air bubbles produced in concrete, though with unfavorable effects on its strength and carbonation. (3) Execution intervals do not contribute much, except to improvement of tensile strength.
