添加石墨与矿粉的沥青化合物的性能评估

资料简介：

　　Summary
　　Fly ash is a fine, glass-like powder recovered from gases created by coal-fired electric power generation. U.S. power plants produce millions of tons of fly ash annually, which is usually dumped in landfills. Fly ash is an inexpensive replacement for portland cement used in concrete, while it actually improves strength, segregation, and ease of pumping of the concrete. Fly ash is also used as an ingredient in brick, block, paving, and structural fills.
　　Fly ash concrete was first used in the U.S. in 1929 for the Hoover Dam, where engineers found that it allowed for less total cement. It is now used across the country. Consisting mostly of silica, alumina and iron, fly ash is a pozzolan--a substance containing aluminous and silicious material that forms cement in the presence of water. When mixed with lime and water it forms a compound similar to portland cement. The spherical shape of the particles reduces internal friction thereby increasing the concrete's consistency and mobility, permitting longer pumping distances. Improved workability means less water is needed, resulting in less segregation of the mixture. Although fly ash cement itself is less dense than portland cement, the produced concrete is denser and results in a smoother surface with sharper detail.
　　综述
　　粉煤灰是从燃煤发电厂废气回收的一种很好的玻璃质粉末。美国电厂每年生产近百万吨粉煤灰,通常用堆填方式处理。粉煤灰是一种廉价的代替水泥用于混凝土的物质，它还可以提高混凝土的强度、和易性和可泵性。粉煤灰作为原料还可用于砖、固体块、路面及结构填充等。
　　粉煤灰混凝土最先用于1929年的美国胡佛水坝，工程师发现粉煤灰可以减少水泥用量. 现已在全世界各地都在使用.粉煤灰含有大量的硅.铝.铁等的火山灰材料.其含有的矾土.硅在水的存在下发生反应,与水和石灰混合形成类似于硅酸盐水泥复合形式. 由于粒子形状是球形，因此减少了内部摩擦增加混凝土的流动性和粘聚性，允许更远的输送距离。改善其工作性意味着减少用水量，从而降低混合物的离析。虽然本身是粉煤灰水泥比硅酸盐水泥密度较低，但生产的混凝土是密实的,且其表面平滑，细致。