水灰比对水泥基材料裂缝自愈合机制的影响

Effect of Water to Cement Ratio on Crack Self-healing Mechanism of Cement Matrix Materials

采用裂缝开口显微观察、超声波脉冲速度测试以及超声波形分析方法,研究水与胶凝材料的质量比(简称水灰比)对水泥基材料裂缝自愈合性能的影响,借助热重分析、物相分析、微观形貌观察等手段,比较不同水灰比的砂浆试块裂缝内表面水化产物及自愈合产物的差异,评价不同水灰比的砂浆试块裂缝自愈合能力。结果表明:随着水灰比的增大,砂浆试块的自愈合能力明显改善,超声波恢复能力增强;水灰比较小的砂浆试块裂缝自愈合的机制是水泥矿物的继续水化,水灰比较大的砂浆试块裂缝自愈合的机制是碳酸钙沉积。

By using methods of crack opening microscopic observation,ultrasonic pulse velocity test,and ultrasonic waveform analysis,effect of mass ratio of water to cementitious materials,i.e.water to cement ratio,on crack self-healing performance of cement matrix materials was researched.Differences of hydration products and self-healing products on inner crack surfaces of mortar samples with different water to cement ratios were compared based on thermogravimetric analysis,phase analysis,and microscopic morphology observation,and crack self-healing ability of the mortar samples with different water to cement ratios were evaluated.The results show that with increase of the water to cement ratio,self-healing ability of the mortar samples is improved obviously and ultrasonic recovery ability is enhanced.The self-healing mechanism of the mortar samples with smaller water to cement ratio is continuous hydration of cement minerals,while the self-healing mechanism of the mortar samples with greater water to cement ratio is deposition of calcium carbonate.