| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a concrete landmark which has a reduced weight and can easily be carried and set, by mixing a cement and water with an aggregate produced by calcining coal ash, pouring the mixture into a mold, and then curing and solidifying the mixture. SOLUTION: This landmark is obtained by mixing a coarse calcined coal ash aggregate having an FM (coarse particle rate) of 6 to 8 with a fine calcined coal ash aggregate having an FM of 2 to 3 in an absolute volume ratio of 1:1, adding a cement to the mixture so that the absolute volume ratio of the coarse aggregate, the fine aggregate and the cement is 3:3:1 mixing the mixture with water to prepare a slurry having a slump value of 20 to 22 cm, pouring the slurry into a mold, and then curing and solidifying the molded product. The coal ash includes the combustion residue of coal used as a heat source in a thermal power station and coal ash collected from combustion furnaces, and is pelletized using a pelletizer and then calcined in a calcination oven to produce an aggregate. The cement includes Portland cement, blast furnace cement and silica cement.</p> |
