高寒地区桥梁混凝土抗氯离子渗透性能研究

Resistance to Chloride Ion Permeation to Concrete Bridges in Alpine Regions

摘要:

依托新疆果子沟特大桥工程，针对高寒区域的气候特征及材料性状，通过正交试验，重点研究了水胶比、粉煤灰掺量、用水量和引气剂掺量等因素对桥梁混凝土抗氯离子渗透性的影响规律；通过深入分析桥梁不同部位及不同配合比混凝土的抗氯离子渗透机理，提出基于抗氯离子渗透性能的高寒区域桥梁混凝土配合比设计参数范围.研究表明：水胶比与用水量对桥梁混凝土的抗氯离子渗透性能影响显著，C30混凝土水胶比（质量比）由045减小到039时，混凝土56d电通量降低约50%；粉煤灰掺量（质量分数）由10%增加到30%时，混凝土电通量总体呈下降的趋势；控制桥梁混凝土中适宜含气量也有利于改善其抗氯离子渗透性能.

Abstract:

With support of Xinjiang Guozigou Bridge project, the influence factor of the resistance to chloride ion permeation to the concrete bridge in alpine area was studied. The mechanism of resistance to chloride ion permeation to the concrete in different positions and with different composition of the bridge concrete was analyzed, then the mix design parameters for the bridge concrete that was suitable to built the bridge with resistance to chloride erosion were proposed. The result shows that the water binder ratio and water content have great effect on the resistance to chloride ion permeation to the concrete bridge. The water binder ratio of C30 grade of concrete is lowered from 045 to 039 and 56 days of electric flux for the concrete is reduced about 50%; electric flux for the concrete is decreased when the use level of fly ash increases from 10% to 30%; suitable air content can improve the resistance to chloride ion permeation to the concrete bridge.