轻骨料混凝土的抗冻性研究

Frost Resistance of Lightweight Aggregate Concrete

抗冻性不足是混凝土耐久性破坏的主要原因之一,轻骨料混凝土弹性能力大,抗冻胀能力强,可以缓解水工建筑物的抗冻性。笔者通过室内试验,研究了水灰比、引气剂掺量变化对轻骨料混凝土抗冻性的影响,试验结果显示:随着水灰比的增大轻骨料混凝土的抗冻性降低,随着引气剂含量的增长,抗冻性先增大后减小。另外还研究了不同冻融介质(水和盐溶液)对轻骨料混凝土抗冻性的影响,试验结果显示:水灰比较大的轻骨料混凝土,在清水中的冻融破坏优于盐溶液的破坏。

Insufficient frost resistance is one of the important reason of the concrete durability. Lightweight aggregate concrete has good elastic capacity. It can alleviate the frost resistance of hydraulic structures. The writer studied the influence of the water cement ratio, air-entraining agent dosage on the frost resistance of lightweight aggregate concrete, through indoor test. The results show that the lightweight aggregate concrete frost resistance is reduced with the increase of water cement ratio, frost resistance first increases and then decreases with the increase of air-entraining agent. The influence of different freezing and thawing medium （water and salt solution） on frost resistance of lightweight aggregate concrete is also studied. The results show that the larger water-cement of the lightweight aggregate concrete, the freeze- thaw damage of water is better than that of the destruction of the salt solution. Key words： frost resistance ; water cement ratio ; air-entraining agent ; salt solution