矿物外加剂对混凝土抗硫酸盐侵蚀性能的研究和评价

Studies and evaluation of sulfate resistance of concrete with mineral admixtures

为考察不同矿物外加剂对混凝土抗硫酸盐侵蚀性能的影响,本文采用ASTMC1202-95A5%Na2SO4溶液浸泡的方法,对掺不同铝含量的粉煤灰及硅灰混凝土的一年龄期膨胀率进行了研究。试验结果显示,掺入粉煤灰、硅灰等矿物外加剂使混凝土膨胀率大幅度降低,25%粉煤灰和10%硅灰双掺混凝土其膨胀率仅为对比组的54 5%;试验结果还显示,掺不同铝含量的粉煤灰混凝土膨胀率基本相近,这表明粉煤灰铝含量不一定是影响混凝土抗硫酸盐侵蚀性能的主要因素。本文还利用Frearson的评价标准对混凝土抗硫酸盐侵蚀性能进行了分析,结果表明掺矿物外加剂混凝土抗硫酸盐侵蚀性能与用抗硫酸盐水泥配制的混凝土性能相当。

In order to understand influences of mineral admixtures on resistance of concrete, the paper studies the expansive ratio of concrete with fly ash of different content of aluminum and silica fume by a oneyear aged expansion experiment with ASTM C120295A. The results show that mixing mineral admixtures such as fiy ash, silica fume, decrease the expansion ratio of concrete. The expansion value of concrete with 25% fly ash and 10% silica fume is only 54.5% of that of control concrete. The results also show that the expansion values of concretes with fly ash of different content of aluminum are nearly equal. It indicates that the aluminum content isn't a main effective factor on sulfate resistance of concrete. At last the paper analyses sulfate resistance of concrete with mineral admixtrues by Frearson method. It shows that sulfate resistance of concrete with mineral admixtures will reach the allowance range of antisulfate affack and is equal to that of concrete mixed by antisulfate attack cement.