论文部分内容阅读
七十年代以来，从国内外水泥外加剂的发展看，减水剂是研究和使用最广泛的一种水泥外加剂。在国外，早在三十年代减水剂已开始在混凝土工程中大量使用，据有关资料介绍，采用外加剂（主要是减水剂）的混凝土数量占混凝土总量50％以上的国家有美国、日本、澳大利亚、西德、苏联等，近年来美国用减水剂的混凝土达1亿吨左右，占美国混凝土年产量的三分之一。在五十年代，不少国家材料协会专门制定了减水剂的技术标准，建立了系列。在国内，五十年代已开始应用，七十年代以来，减水剂的研究和应用有了极大的发展，新品种不断增多，而且减水剂的规格系列正在逐步形成。减水剂之所以得到广泛应用，其技术经济效益有以下五点（指用于混凝土而言）：
Since the 1970s, from the perspective of the development of cement admixture at home and abroad, water-reducing agent is the most widely used cement admixture for research and use. In foreign countries, as early as the 1930s, superplasticizers had begun to be used in large quantities in concrete projects. According to relevant information, the countries that use admixtures (mainly water-reducing agents) account for more than 50% of the total amount of concrete. In Japan, Australia, West Germany, and the Soviet Union, in recent years, the concrete used for water-reducing agents in the United States has reached 100 million tons, accounting for one-third of the annual output of concrete in the United States. In the 1950s, many national material associations specially formulated technical standards for water-reducing agents and established series. In the country, it began to be used in the 1950s. Since the 1970s, the research and application of water-reducing agents have grown tremendously, new varieties have been increasing, and the specification series of water-reducing agents are gradually being formed. The reason why the water-reducing agent is widely used is that its technical economic benefits are as follows: