冻融循环条件下引气剂对混凝土抗渗性和抗冻性影响的试验研究

通过电通量试验、表面气体渗透试验和硬化混凝土气泡参数试验,对冻融后混凝土的抗渗性及抗冻性进行了分析研究。试验结果表明引气剂可大范围阻断毛细气孔通路,引气剂对冻融次数越多的混凝土试件抗渗改善效果显著。随着混凝土冻融次数的增加,混凝土的电通量、表面气体渗透深度和表面气体渗透系数均逐渐增大。在相同冻融次数下,随着引气剂掺量的增加,表面气体渗透深度和表面气体渗透系数逐渐减小,抗渗透能力提升。在合理引气的条件下,引气剂掺量越多,引入的小气泡越多,气泡间距系数越小,改善了冻融循环条件下混凝土的抗渗性和抗冻性,提高了混凝土的耐久性。

Experiment Study on the Effect of Air Entraining Agent on Permeability Resistance and Freezing Resistance of Concrete with Freezing and Thawing

Through the electric flux test, surface gas permeation test and bubble parameters of hardened concrete tests, the permeability resistance and freezing resistance of concrete with freezing and thawing were analyzed in this paper. The experimental results show that the air permeability agent can block the capillary porosity widely, and the anti-permeability of the concrete is significantly improved. With the freezing-thawing cycles increasing, the concrete electric flux, surface gas penetration depth and surface gas permeability coefficient increased gradually. Under the same freezing-thawing times, the surface gas penetration depth and surface gas permeability coefficient decreased gradually with the increase of the amount of air entraining agent, the permeability resistance was improved. Under the reasonable content of air entraining agent, with the increase of the amount of air entraining agent, the more small bubbles are introduced and the smaller the bubble spacing coefficient is. The improvement effect of the permeability resistance and freezing resistance of concrete with freezing and thawing is obvious, and the durability of concrete is improved.