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Na₂CO₃溶液（0、2%、4%、6%）环境下混凝土裂缝的自愈合性能。结果表明，Na₂CO₃溶液对混凝土裂缝的自愈合效果明显优于水；不同浓度Na₂CO₃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，后随龄期的延长趋于平缓；6%Na₂CO₃溶液环境下，混凝土强度恢复效果最明显，49d时完全恢复，60d时强度恢复率增至106.1%；2%Na₂CO₃溶液环境下，60d时混凝土强度恢复率仅为73.5%；4%Na₂CO₃溶液环境下，混凝土强度恢复效果处于两者之间。随Na₂CO₃溶液浓度的增大，裂缝中C-S-H凝胶、CaCO₃晶体等水化产物增多，体积增大，二者通过填充作用和胶结作用，使裂缝逐渐愈合。

Abstract: Concrete self-healing performances under different concentration of sodium carbonate solution（0，2%，4%，6%） were studied by analyzing mechanical property, crack width, phase composition and microstructure before and after the repairment of concrete crack. The experimental results indicated that the self-healing capacity of concrete curing in sodium carbonate solution was much better than that of concrete curing in water. In different concentrations of sodium carbonate solution, the early rising rate of strength and ultrasonic velocity of concrete sample was high, along with the prolongation of curing age, the rising rate of strength and ultrasonic velocity leveled off. Concrete curing in the 6% sodium carbonate solution showed the best self-healing performance and its compressive strength recovered completely in the curing age of 49 days, and the strength restoration ratio was 106.1% in the curing age of 60 days. The strength restoration ratio of concrete curing in 2% sodium carbonate solution was only 73.5% in the curing age of 60 days. 4% sodium carbonate solution showed a middle self-healing performance. The amount and size of hydration products, such as C-S-H gel and calcium carbonate, increased with the increase of sodium carbonate solution concentration. These hydration products made the crack healed gradually through filling action and cementation action.