The free frame construction method use surface blowing material and the free frame construction method null which uses

摘要

PROBLEM TO BE SOLVED: To improve the workability while using a small free frame by providing cement mortar, an accelerating agent containing calcium aluminate and a retarder so to have a specified working time, and setting a constant compression strength. ;SOLUTION: Calcium aluminate is contained as an accelerating agent so as to give the quick setting property to the cement mortar, and hydration of the cement is accelerated so as to improve the strength of the cement mortar at the initial time. Furthermore, use for a small frame such as a free frame is enabled, and the retarder is added to the cement mortar so as to prolong the working time, in which leveling is possible. In this case, working time is set at 5-120 minutes, and compression strength after 28 days is set at 25 N/mm² or more. A lower reinforcement and a metal net are located in the natural ground, and an upper reinforcement is arranged, and both the upper and the lower reinforcement are connected to each other, and the slope spraying material sprayed to the free frame is leveled by a trowel. With this structure, strength realizing property is improved so as to reduce the spraying thickness in comparison with a conventional one, and the working time is shortened, and the efficiency is improved.;COPYRIGHT: (C)1999,JPO