所谓混凝土,通常是指水泥、砂子、石子、水以及必要时添加的化学外加剂按一定比例混合搅拌,再经过硬化而形成的复合材料。自从1824年波特兰水泥(即普通硅酸盐水泥)发明之后,就有了现在的混凝土。混凝土的原料易得、成本较低、防火耐久、可按照人们的意愿塑造成各种断面和外形,恭顺地为人类服务。近几年,农房用混凝土材料发展很快。已有10％新建农房 The so-called concrete, usually refers to cement, sand, stones, water, and if necessary, add the chemical admixture by a certain proportion of mixing and then hardened to form a composite material. Since the invention of Portland cement (ie Portland cement) in 1824, there is now concrete. The raw materials of concrete are easy to obtain, low in cost, durable in fire, and can be shaped into various sections and shapes in accordance with people’s wishes, and serve humanity with respect. In recent years, the use of concrete materials in rural housing has developed rapidly. Already 10% new rural house