Cement constituent, cement hardening body and the production manner, and cast-in-place lining construction method

摘要

PURPOSE: To enable early demolding of molded cement without using a steam- curing process and improve the development of the strength by compounding a specific Portland cement with anhydrous gypsum, aluminum sulfate, an alkali metal aluminate and a nitric acid salt. CONSTITUTION: This cement composition is obtained by compounding 100 pts.wt. of a Portland cement having a Blaine value of 3,500-7,000cm2 /g and a 3CaO.SiO2 content of =60wt.% with 1-5 pts.wt. of anhydrous gypsum having a Blaine value of =2,500cm2 /g, 0.2--3 pts.wt. (in terms of anhydride) of aluminum sulfate, 0.1-0.8 pts.wt. of an alkali metal aluminate and 0.5-5 pts.wt. of a nitric acid salt. A concrete produced by kneading the composition with water at a water/ binder ratio of 25-50wt.% is placed and cured under the application of gravitational acceleration of 1-50G and a construction joint is performed by shifting the mold.