水胶比和含气量对蒸养混凝土抗冻性的影响

摘要

为研究水胶比和含气量对蒸养混凝土抗冻性的影响,采用快冻法分别测试了不同水胶比和含气量的蒸养混凝土经350次冻融循环后的质量损失率和相对动弹模量,分析了质量损失率与外观变化的关系.研究结果表明,水胶比对蒸养混凝土的抗冻性影响较大,水胶比越大,抗冻性越差,质量损失率越大,冻融前后的外观变化越明显;在低水胶比下,即使不掺加引气剂,蒸养混凝土也具有较好的抗冻性.掺入适量引气剂可以保证蒸养混凝土抗冻性良好,含气量在3％～5％范围内时,含气量的变化对蒸养混凝土的抗冻性影响不大.%To study the effects of water-binder ratio and air content on the frost resistance of steam curing concrete,we tested the loss rates of quality and the relative dynamic modulus of different water-binder ratio and air content steam curing concrete after 350 cycles of rapid freeze-thaw test,and analyzed the relationship of the loss rate of quality and appearance changing.The results show that the influence of water-binder ratio on the frost resistance of steam curing concrete is bigger than the one of air content.When the water-binder ratio is higher,the frost resistance is poorer,the loss rate of quality is larger and the appearance changing after freeze-thaw test is more obvious.Under the low water-binder ratio,the steam curing concrete has good frost resistance character even without adding air entraining agent.Adding certain amount of air entraining agent can ensure that the frost resistance of steam curing concrete on a better level.When the gas content is in the range of 3％ to 5％,the effect of the air content on the frost resistance of steam curing concrete is little.