掺Ⅱ级粉煤灰胶砂试件在高浓度硫酸盐侵蚀下的破坏特征与破坏机理分析

Destruction Features and Failure Mechanism Analysis of Mixed Ⅱ Fly Ash Motar Specimens in the High Concentrations of Sulfate Solution

按高性能混凝土配比方法制作不同水胶比、Ⅱ级粉煤灰不同掺量的胶砂试件,进行硫酸盐侵蚀试验。采用扫描电镜(SEM)和能谱(EDS)对试件进行微观观测、分析,结果表明:在低水胶比情况下,掺粉煤灰的胶砂试件受高浓度硫酸盐侵蚀破坏的类型是石膏型破坏,未产生钙矾石(Aft)型侵蚀破坏;侵蚀破坏发生在试件表层,侵蚀破坏层的厚度主要与水胶比、粉煤灰掺量、侵蚀龄期、侵蚀溶液浓度等因素有关。

The capability of resisting sulfate corrosion was tested among the different eontens of Ⅱ fly ash and different water-hinder ratios of mortar specimens which were made by the method of high performance concrete. Microscopic observation and analysis of mortar specimens was observed with scanning electron microscope （SEM） and energy dispersion spectrum （EDS） . The results indicated that under the low water-hinder ratio, Specimen erosion damage type is gypsum failure type, not ettringite （Aft） type erosion damage. We also found that the erosion only Occurred in the surface and the factors affecting the thickness of Erosion damage layer mainly include the water-binder ratio、the contens of Ⅱ fly ash,the erosion ages,the erosion solution concentration, etc.