| 摘要 |
PURPOSE: To provide primary lining having high reliability with respect to strength by adding cellulose consistent agent, water reducing agent, accelerator of hardening, and setting modifier to concrete in pressurization, filling, and placing of lining concrete by a shield machine. CONSTITUTION: Cellulose consistent agent, water reducing agent, accelerator of hardening which produces required strength within a predetermined time and promotes hardening, and setting modifier for adjusting hardening time are added to concrete for cast-in-place concrete lining. It is placed in an annular space formed among a shield tail plate of a shield machine, a concrete pressurizing plate, an inner form, and a front face of existing lining concrete. Consequently, it is possible to eliminate the occurrence of a tail void and construct primary covering having high reliability with respect to strength. |
