Abstract: The sulphate corrosion resistance of different alkali-activated materials, including alkali-activated fly ash (AAFA) and alkali-activated slag (AASL) was studied. Based on the analysis of traditional test indexes, including mass loss, cross-section size and compressive strength, combined with the micro test methods of X-ray diffraction (XRD) and scanning electron microscope (SEM), the effects of different curing ages, sulfate solution concentration and soaking time of porous concrete specimens on the sulfate corrosion resistance of porous concrete with alkali-activated cementitious materials were studied. The results show that different alkali-activated cementitious materials have different deterioration modes. Ordinary porous concrete (OPC) is mainly reflected in the attenuation of mass and cross-section size, AASL is mainly manifested by the increase of mass and the expansion of cross-section size and the main product after OPC and AASL corrosion is gypsum. AAFA has no obvious change in mass and cross-section size, whose erosion process is dealumination and alkalization of sodium aluminosilicate crystals and the formation of a small amount of gypsum, accompanied by the reduction of compressive strength.

Key words: highway engineering; porous concrete; alkali-activated material; sulphate corrosion; mechanism

摘要： 针对两种碱活化粉煤灰（AAFA）和碱活化矿渣（AASL）多孔混凝土的耐硫酸盐浸蚀性进行研究，采用传统试验指标，包括质量损失、横截面尺寸、抗压强度分析，结合X射线衍射（XRD）和扫描电镜（SEM）等微观测试手段，研究不同多孔混凝土试件养护龄期、硫酸盐溶液浓度及浸蚀时间对碱激发胶凝材料多孔混凝土耐硫酸盐浸蚀性能的影响。结果表明：不同碱激发胶凝材料具有不同的劣化方式，普通多孔混凝土（OPC）主要体现在质量和横截面尺寸的衰减，AASL主要表现为质量的增加以及横截面尺寸的膨胀，且OPC和AASL浸蚀后的主要产物为石膏；AAFA没有明显的质量及横截面尺寸变化，其浸蚀过程为硅铝酸钠结晶的脱铝和碱化以及少量石膏的生成，伴随着抗压强度的降低。

关键词: 道路工程；多孔混凝土；碱激发材料；硫酸盐浸蚀；机理