吸附区粉煤灰混凝土抗硫酸盐腐蚀性能研究

Research on the sulfate corrosion resistance of fly ash concrete in adsorption area

采用浸泡、半浸泡的试验方法,定期检测混凝土的超声声速和抗压强度,并观察不同腐蚀期试件的表观现象.结果表明:随着腐蚀时间的增长,试件腐蚀层厚度逐渐增加,腐蚀速率先降低后升高最后趋于稳定;抗压强度先增大后减小,强度损失度逐渐增大;吸附区普通混凝土破坏最严重,浸泡区粉煤灰混凝土破坏最轻微.通过机理分析建立半浸泡混凝土受硫酸盐腐蚀性能的退化模式.

The ultrasonic velocity and compressive strength of concrete were examined regularly using immersion and semi-immersion methods, the appearances of specimen were observed during different corrosion periods. Results show that with increasing corrosion time, the thickness of eorrosion layer and the degree of strength loss increase gradually; the corrosion rate firstly decreases and then increases, and finally tends to be stable, while the compressive strength shows an opposite trend; normal concrete in adsorption area is damaged seriously, and the fly ash concrete in the soak zone, instead, show the slightest damage. By analyzing the mechanism, a degradation model of concrete under sulfate corrosion was established.