新疆阿拉尔地区C30负温混凝土受冻临界强度试验研究

Experimental study on the critical freezing strength of C30 negative temperature concrete in the Alaer region of Xinjiang

研究了不同配合比下C30混凝土在-5~-20℃受冻温度下的受冻临界强度,同时采用快冻法对达到受冻临界强度的混凝土在-15℃温度下进行冻融循环试验。试验结果表明:未掺防冻剂混凝土在受冻时,其预养护时间和受冻临界强度具有规律性的变化。受冻温度愈低,混凝土预养护时间愈长,受冻临界强度愈大。但在相同受冻温度下,掺防冻剂负温混凝土的受冻临界强度呈不同程度的降低,且无规律性。掺与未掺防冻剂负温混凝土在达到受冻临界强度后,后期抗压强度均有所保障,但抗冻性较标准养护条件下的混凝土劣化严重。

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 temperature concrete mixed with antifreeze decreases to varying degrees and is irregular.After reaching the critical freezing strength,the later compressive 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.