The critical strength of C30 concrete under different mix ratios at from-5℃ to-20℃ was studied.At the same time,the rapid freezing method was used to conduct freeze-thaw cycle experiments on concrete that had reached the critical freezing strength at a temperature of-15℃.The experimental results show that the pre-curing time and critical freezing strength of concrete without antifreeze agent exhibit regular changes when subjected to freezing.The lower the freezing temperature,the longer the pre-curing time of concrete,and the greater the critical freezing strength.However,at the same freezing temperature,the critical freezing strength of negative tempera-ture concrete mixed with antifreeze decreases to varying degrees and is irregular.After reaching the critical freezing strength,the later com-pressive strength of negative temperature concrete with and without antifreeze is guaranteed,but the frost resistance is more serious than that of concrete under standard curing conditions.
关键词
负温混凝土/受冻临界强度/预养护时间/抗冻性
Key words
negative temperature concrete/critical freezing strength/pre-curing time/frost resistance
万方数据