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混凝土的冻融破坏是当今混凝土耐久性问题的一个重要方面,在混凝土中掺加适量的引气剂能显著提高混凝土的抗冻性,从而增加混凝土的服役寿命。对混凝土不同冻融循环次数后的相对动弹性模量、失重率做了具体分析,并且对试件从外及里各部分进行了毛细吸水试验。结果表明:引气混凝土经过300次冻融循环后仍保持良好的抗冻性,失重率仅为0.3%,普通混凝土的抗冻性较差,100次循环后失重率达到0.9%;未掺加引气剂的混凝土试件经不同冻融循环后外部毛细吸收系数A值均大于其内部的毛细吸收系数,试件内外损伤程度不同。
Freeze-thaw damage of concrete is an important aspect of the durability of concrete today. Addition of proper amount of air-entraining agent in concrete can significantly increase the frost resistance of concrete and thus increase the service life of concrete. The relative dynamic elastic modulus and weight loss rate of concrete after different freeze-thaw cycles were analyzed in detail, and the capillary suction test was carried out on the specimens from the outer part and the inner part. The results showed that the air-entrained concrete still maintained good frost resistance after 300 freeze-thaw cycles, the weight loss rate was only 0.3%, the ordinary concrete was poor in frost resistance and the weight loss rate was 0.9% after 100 cycles. Air-entrained concrete specimens after different freeze-thaw cycles, the external capillary absorption coefficient A value is greater than its internal capillary absorption coefficient, the degree of damage inside and outside the specimen is different.