The present study aimed to investigate the durability and microstructure evolution of road base materials (RBM) prepared from red mud and flue gas desulfurization fly ash. The durability testing showed that the strength of RBM with the blast furnace slag addition of 1wt%, 3wt% and 5wt% reached 3.81, 4.87, and 5.84 MPa after 5 freezing–thawing (F–T) cycles and reached 5.21, 5.75, and 6.98 MPa after 20 weting–drying (W–D) cycles, respectively. The results also indicated that hydration products were continuously formed even during W–D and F–T exposures, resulting in an increase of the strength and durability of RBM. The observed increase of macropores (>1 μm) after F–T and W–D exposures suggested that the mechanism of RBM deterioration is pore enlargement due to cracks that develop inside their matrix. Moreover, the F–T exposure showed a greater negative effect on the durability of RBM compared to the W–D exposure. The leaching tests showed that sodium and heavy metals were solidified below the minimum requirement, which indicates that these wastes are suitable for use as a natural material replacement in road base construction.

本研究旨在研究由赤泥和烟气脱硫粉煤灰制备的路基材料（RBM）的耐久性和微观结构演变。耐久性测试表明，在5个冻融（F-T）循环后，高炉矿渣分别添加1wt％，3wt％和5wt％的RBM的强度分别达到3.81、4.87和5.84 MPa，分别达到5.21、5.75和经过20个湿-干（W-D）循环后，分别为6.98 MPa。结果还表明，即使在W-D和F-T暴露过程中，水合产物也不断形成，从而提高了RBM的强度和耐久性。F-T和W-D暴露后观察到的大孔增加（> 1μm）表明，RBM恶化的机理是由于其内部出现裂纹而导致的孔扩大。此外，与W-D暴露相比，FT暴露对RBM的持久性具有更大的负面影响。浸出试验表明，钠和重金属的固化量低于最低要求，这表明这些废物适合用作路基建设中的天然材料替代品。