摘要 |
PROBLEM TO BE SOLVED: To provide a protective plate for an underground buried object which consists of a cement hardened body having high compressive strength (for example, 330 N/mmor more) and is less likely to be cut or damaged by an asphalt cutter or the like.SOLUTION: A protective plate 1 for an underground buried object consists of a cement hardened body. The cement hardened body is formed by hardening a cement composition which contains cement, silica fume having a BET specific surface area of 15-25 m/g, an inorganic powder having a 50% cumulative particle size of 0.8-5 μm, an aggregate having a maximum particle size of 1.2 mm or less, a high performance water reducing agent, an antifoaming agent, and water, and in which the content of the cement is 55-65% by volume, the content of the silica fume is 5-25% by volume, and the content of the inorganic powder is 15-35% by volume in 100% by volume of the total amount of the cement, silica fume and inorganic powder.SELECTED DRAWING: Figure 1 |