低温变温(5℃→-3℃)养护下不同水灰比混凝土抗氯离子渗透性试验研究

Effect of Cryogenic Variable Temperature( 5 ℃→- 3 ℃) Curing Condition and Water Cement Ratio on the Resistance to Chloride Ion Permeability of Concrete

为了研究低温变温（5℃→-3℃）养护条件下不同水灰比（0．24、0．27、0．31、0．38）混凝土的抗氯离子渗透性，采用直流电量法对低温变温养护下和标准养护下养护28d的混凝土进行了抗氯离子渗透性研究。试验结果表明：低温变温养护下混凝土的电通量随着水灰比的增大而增大，这与标准养护下混凝土电通量的规律一致；低温变温养护下混凝土电通量与标养下混凝土电通量的比值随着水灰比的增大而减小；低温变温养护条件下混凝土的电通量是标准养护下混凝土的1．60～1．65倍；低温变温养护条件下混凝土的初始电流是标准养护下混凝土的1．55～1．58倍。说明在低温变温养护条件下混凝土的抗氯离子渗透性较差。

In order to study the resistance to chloride ion permeability for concrete with different water cement ratio（0.24,0.27,0.31,0.38） under cryogenic variable temperature（5℃→-3℃ ） curing, DC method was used to study the resistance to chloride ion permeability for concrete cured 28d at cryogenic variable temperature and standard curing condition. The results show that the electric flux will improve with the increasing of water cement ratio of the concrete which cured under cryogenic variable temperature, which have the same law with the concrete cured under standard curing condition, and the electric fluxg ratio of cryogenic variable temperature curing and standard curing is becoming smaller with the increasing of water cement ratio of the concrete. By comparing the electric flux and initial electric current respectively which cured under cryogenic variable temperature and standard curing condition finds out that the electric fluxg ratio of cryogenic variable temperature curing and standard curing is between 1. 60 and 1.65, the initial electric current ~s ratio of cryogenic variable temperature curing and standardcuring is between 1.55 and 1.58. That shows that the resistance to chloride ion permeability for concrete which cured under cryogenic variable temperature was poorer.