Cement composition and manufacturing method for cement cured body using same

A method of producing a cementitious cured body made of a cement composition,

• the cement composition comprising:
• cement;
• silica fume having a BET specific surface area of from 10 m2/g to 25 m2/g;
• an inorganic powder having a 50% cumulative particle size of from 0.8 μm to 5 μm;
• a fine aggregate having a maximum particle size of 1.2 mm or less;
• a water reducing agent;
• an antifoaming agent;
• and
• water,
• wherein a ratio of the cement is from 55 vol % to 65 vol %, a ratio of the silica fume is from 5 vol % to 25 vol %, and a ratio of the inorganic powder is from 15 vol % to 35 vol % in a total amount of 100 vol % of the cement, the silica fume, and the inorganic powder;
• the method comprising:
• a molding step of setting the cement composition into a mold to provide an uncured molded body;
• a room temperature curing step of subjecting the uncured molded body to sealed curing or atmospheric curing at from 10° C. to 40° C. for 24 hours or more, followed by demolding the molded body from the mold, to thereby provide a cured molded body;
• a water absorbing step of immersing the cured molded body into water under reduced pressure and causing the cured molded body to absorb water;
• a heat curing step of subjecting the cured molded body to steam curing or hot water curing at from 70° C. to 95° C. for 24 hours or more, to thereby provide a cured body after heat curing;
• and
• a high-temperature heating step of heating the cured body after the heat curing at from 150° C. to 200° C. for 24 hours or more, to thereby provide the cementitious cured body.