混凝土冬季施工多年来一般均采用外加热的方法,使混凝土在正温下硬化。这样造成混凝土施工麻烦,大型设施增加,造价较高,一般混凝土造价增加30～40元/m~3,相当于混凝土和钢筋混凝土的造价25％～50％。五十年代曾在混凝土中大量地掺入氯盐(NaCl,CaCl_2)作为负温防冻早强的外掺剂,实践中大量加入氯盐,促使了钢筋严重锈蚀,因此国家规定在钢筋混凝土中限量使用氯盐。为了解决负温下混凝土施工,寻找化学方法和物理方法 Concrete winter construction over the years are generally used external heating method, so that concrete at a positive temperature hardening. This caused concrete construction problems, large facilities increase, higher cost, the general cost of concrete increased 30 ~ 40 yuan / m ~ 3, equivalent to the cost of concrete and reinforced concrete 25% to 50%. In the 1950s, a large amount of chloride (NaCl, CaCl 2) was incorporated into concrete as an external admixture of negative temperature and antifreeze early strength. In practice, a large amount of chloride salt was added to promote the severe corrosion of steel. Therefore, the limit stipulated by the state in reinforced concrete Use chloride salts. In order to solve the negative temperature concrete construction, looking for chemical methods and physical methods