混凝土渗透性及引气作用对耐久性的影响

论述了混凝土渗透性与耐久性,引气与耐久性的关系;探讨了引气改善混凝土耐久性的作用机理.混凝土渗透性与Cl-离子侵入、碳化、硫酸盐化学侵蚀有一定相关性.渗透性与其他一些耐久性如抗冻性、硫酸盐结晶破坏、碱集料反应等关系不大.在保证混凝土具有一定强度的前提下,引气可显著改善混凝土综合耐久性能.在同强度条件下,引气可改善混凝土的抗渗性能,有利于混凝土抗Cl-离子侵入、硫酸盐化学侵蚀、碳化等化学侵蚀引起的破坏,引气还可显著改善抗冻、碱集料反应和盐结晶等因膨胀引起的破坏.

Effect of Permeability of Concrete and Air Entrainment on Durability of Concrete

The paper presents an investigation of the relationship between the permeability and the durability,and a study of the effect of air entrainment on durability and the improvement mechanism of concrete durability by air entrainment.The permeability is found to be related to some degree with the durability when the concrete is exposed to the chemical attacks such as chlorine ion intrusion,carbonation and sulfate chemical erosion,but no obvious relation is found as to the durability against the expansion caused by freeze,sulfate crystallization and alkali aggregate reaction.Study results show that the comprehensive durability can be improved by air entrainment in comparison with the ordinary concrete,and the concrete resistance against permeability is improved accordingly at equal compressive strength.