【摘要】 再生骨料和粉煤灰可作为固废辅助材料用于混凝土的制备，为提高粉煤灰再生混凝土的应用价值，对不同再生骨料替代率（0、30%、60%、100%）粉煤灰再生混凝土在硫酸盐冻融耦合侵蚀作用下的耐久性、孔隙结构表征及微观结构进行探讨。研究结果表明：在硫酸盐冻融耦合侵蚀作用下，再生骨料降低了混凝土的耐久性，其骨料替代率越高，损伤程度越大；从孔隙结构表征分析，再生骨料的加入劣化了混凝土的孔隙结构，即孔隙率和孔隙最大直径增大，有害孔隙增多，再生骨料替代率越大，孔隙和裂缝的连通性越高，易造成结构损伤；从不同循环次数的微观结构来看，侵蚀性产物（AFt）主要生成在再生骨料的界面薄弱区，界面薄弱区的孔隙和裂缝是影响再生骨料耐久性的主要因素，为粉煤灰再生混凝土的实际工程应用提供参考。更多还原

【Abstract】 Recycled aggregates and fly ash can be used as solid waste auxiliary materials for concrete preparation,in order to improve the application of fly ash recycled concrete,this paper explores the durability,pore structure characterization,and microstructure of fly ash recycled concrete with different recycled aggregate substitution rates(0,30%,60%,and 100%)under sulfate freezing and fusion coupled erosion.The results show that recycled aggregate reduces the durability of concrete under sulfate freeze-fusion coupled erosion,and the higher the aggregate substitution rate,the greater the degree of damage;from the analysis of pore structure characterization,the addition of recycled aggregate deteriorates the pore structure of concrete,the pore rate and the maximum diameter of the pore increase,and the number of hazardous pores increases,and the greater the substitution rate of the recycled aggregate,the greater the connectivity of pores and cracks,which is prone to cause structural damage;from the microstructure of different cycle times,the erosive products(AFt)were mainly generated in the interfacial weak zone of recycled aggregate,and the pores and cracks in the interfacial weak zone were the main factors affecting the durability of recycled aggregate,which provides a reference for the practical engineering application of fly ash recycled concrete.更多还原