低温减慢水泥的水化速率,在寒冷气候下,需采用各种办法对此进行补偿,使砼达到所控制的凝结时间,常用的方法是掺入早强剂,加热拌合水和骨料是另一种方法,这两种方法都是局限性,恃别是气温温度低于砼冻结温度的情况下,此时砼在初凝到已经冻结,使得普通早强剂失效;而加热拌合水和骨料,又使砼与周围空气之间的温差增大,加剧塑性收缩裂缝。一、塑性收缩裂缝 The low temperature slows down the rate of hydration of the cement. In cold climates, various methods are required to compensate for this, so that the cesium achieves the controlled setting time. The commonly used method is to incorporate early strength agents, heated mixing water and aggregates. Another method, both of which are limitations, is the case when the temperature of the air is lower than the freezing temperature of the crucible. At this time, the crucible is frozen at the beginning of freezing, which makes the ordinary early strength agent ineffective; and heating and mixing Water and aggregates increase the temperature difference between the helium and the surrounding air and aggravate plastic shrinkage cracks. First, plastic shrinkage cracks