Cement admixture for long distance pumping and injection method

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive plastic injection material by which the hardening and settling of an A material being a cement milk in a long distance piping can be prevented, the A material can remain in the piping during night (during daytime in the case of nighttime construction), thereby work for discarding of the A material in the piping and for cleaning the piping can be drastically reduced and a construction period and a manpower can be reduced.SOLUTION: An admixture for cement for long distance pressure fed is constituted by containing 5 to 80 parts of a cellulose derivative to 100 parts of dextrin. An injection construction method is constituted by mixing 400 to 3,000 pts.vol. of the A material being the cement milk containing 0.3 to 2 parts of the admixture for cement for long distance pressure feed and 100 pts.vol. a B material being a plasticizer constituted by mixing a setting accelerator comprising calcium aluminate and gypsum and an acrylic ester copolymer emulsion to 100 parts of cement directly before injection.