粉煤灰混凝土的碳化-冻融特性研究

Research on Carbonation and Freeze-thaw Characteristics of Fly Ash Concrete

为了分析粉煤灰混凝土的碳化-冻融特性,制备了不同粉煤灰掺量的混凝土样品,利用室内试验方法对混凝土样品进行冻融循环和碳化,分析混凝土样品的质量损失率、相对动弹性模量和碳化面积随粉煤灰掺量和冻融-碳化周期的变化规律。研究结果表明:在冻融-碳化条件下,粉煤灰混凝土的质量损失率、弹模损失率以及碳化面积率均随粉煤灰掺量的增大出现了先增大后减小再增大的现象;对比分析结果表明,粉煤灰混凝土的碳化能够在一定程度上提高其抗冻能力;粉煤灰混凝土的碳化面积率随着冻融-碳化循环次数的增加而增大,且当冻融-碳化循环大于一定周期后,碳化面积趋于稳定。

To analyze the carbonation and freeze-thaw characteristics of fly ash concrete, the concrete samples with variable dosage of fly ash were made. The mass loss rate, relative dynamic elastic modulus and the carbonation area change laws of concrete samples with different fly ash contents and carbide freeze-thaw cycles were analyzed with the indoor test method of freeze-thaw cycle and carbonation. The results showed that: under the condition of freeze-thaw and carbonization, the mass loss rate, elastic mold loss rate and carbonization area rate of fly ash concrete samples all increased first, then decreased and then increased with the increase of fly ash content. Comparative analysis results showed that carbonization of fly ash concrete improved its frost resistance to a certain extent;the carbonization area rate of fly ash concrete increased with the increase of the number of freeze-thaw carbonization cycles, and the carbonization area tended to be stable when the freeze-thaw carbonization cycle was larger than a certain period.