针对西北地区混凝土结构遭受硫酸盐侵蚀和冻融循环双重破坏的问题,采用相对动弹性模量、质量损失率、抗压抗蚀系数为主要评价指标,研究分析水胶比对混凝土耐久性能的影响。同时,采用微观扫描电镜(SEM)对混凝土侵蚀破坏机理进行分析。研究结果表明,水胶比由0.4下降到0.3时,混凝土抗压抗蚀系数明显提高、质量损失率明显降低,降低水胶比可以有效提高混凝土结构的耐久性能;混凝土破坏主要表现为表面剥蚀破坏,剥蚀层有侵蚀产物石膏生成。 In view of the problem that the concrete structures in northwest China suffer from double damage of sulfate erosion and freeze-thaw cycle, the relative dynamic elastic modulus, mass loss rate and compressive and anticorrosion coefficient are taken as the main evaluation indexes to study the effect of water-binder ratio on the durability of concrete . At the same time, the erosion mechanism of concrete was analyzed by microscopic scanning electron microscope (SEM). The results show that the compressive and anti-corrosion coefficient of concrete increases obviously and the mass loss rate decreases obviously when the ratio of water to binder decreases from 0.4 to 0.3. The decrease of water-cement ratio can effectively improve the durability of concrete structure. The concrete failure is mainly caused by surface erosion and destruction , Erosion layer gypsum erosion products generated.