| 摘要 |
PROBLEM TO BE SOLVED: To provide a grating which is improved in production efficiency and design, and hardly degrades its mechanical strength, durability, and appearance even after a long service life. SOLUTION: The grating 1 is formed of a cement cured body containing cement, pozzolan impalpable powder having an average grain size of 1.0μm or less, fine aggregate having a maximum grain size of 2 mm or less, metallic fibers or organic fibers, ground quartz having an average grain size of 3 to 20μm, fiber powder or flaky powder having an average grading of 1 mm or less, a water reducing agent, and water. The grating 1 has its upper surface 2 and its lower surface 3 formed like a rectangle, and has a number of through holes 5 penetrating from the upper surface 2 to the lower surface 3. The ratio of the total area of the through holes 5 to a vertically projected area of the grating 1 ranges from 20 to 60 %. COPYRIGHT: (C)2004,JPO
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