中文摘要：

通过分析混凝土裂缝愈合前后的力学性能、裂缝宽度、物相组成和组织结构，研究了不同浓度NaCl溶液（0、2％、4％、6％）环境下混凝土裂缝的自愈合性能。结果表明：NaCl溶液对混凝土裂缝的自愈合效果明显优于水；不同浓度NaCl溶液环境下，混凝土的强度、波速均随龄期延长逐渐增大，且增长速率前期较大，然后随龄期的延长趋于平缓；6％NaCl溶液环境下，混凝土强度恢复效果最明显，35d时完全恢复，60d时强度恢复率增至108．3％。2％NaCl溶液环境下，混凝土强度60d时接近完全恢复，强度恢复率为96．2％。4％NaCl溶液环境下，混凝土强度恢复效果处于两者之间；随NaCl溶液浓度的增大，裂缝中C—S—H凝胶、钙矾石、F盐等水化产物逐渐增多，体积增大，三者通过填充作用和胶结作用，使裂缝逐渐愈合。

英文摘要：

Concrete self - healing performance under different concentration of sosium chloride solution （ 0,2%, 4%, 6% ） on concrete self - healing capacity were studied by analyzising mechanical property, crack width, phase composition and microstructure before and after the repairment of concrete crack. The experimental results indicate that the self - healing capacity of concrete curing in sodium chloride solution is much better than that of concrete curing in water. In a certain range of curing age, the early rising rate of strength and ultrasonic velocity of concrete sample is high, along with the prolongation of curing age, the rising rate of strength and ultrasonic velocity levelled off. Concrete curing in the 6% sodium chloride solution showed the best self - healing performance and its compressive strength recovered completely in the curing age of 35 d, and the strength restoration ratio is 108.3%in the curing age of 60 d. The 4%sodium chloride solution show a middle selfhealing performance. The amount and size of hydration products, such as ettringite, C-S-H gel and Freide＇s salt, increased with the increase of sodium chloride solution concentration. These hydration products made the crack healed gradully through filling action and cementation action.