一、问题的提出兰州地区极端最低气温为-21.1℃,月平均最低气温为-7.3℃(气象资料),在一月份当连续多日的全天平均气温低于-3℃时,使用钢模浇注框架混凝土,由于钢的导热系数(50kcal/m·h·℃)是木模(0.2kcal/m·h·℃)的250倍,热混凝土浇入后,混凝土和钢筋间会不会形成冰冻层而大幅度降低二者之间的粘结力?混凝土与钢模的接触面会 I. Problems raised The extreme minimum temperature in Lanzhou is -21.1°C, and the monthly average minimum temperature is -7.3°C (meteorological data). In January, when the average temperature of the whole day for several days is below -3°C, the steel mold is used. Casting frame concrete, because the thermal conductivity of steel (50kcal/m·h·°C) is 250 times that of the wooden mold (0.2kcal/m·h·°C), after the hot concrete is poured, the concrete and the steel bars will not form frozen. Layers and significantly reduce the adhesion between the two? Contact surface of concrete and steel mold