基于外部供应修复剂系统的自修复水泥基材料研究

Self-healing Cementitious Materials Based on External Supply Healing Agent System

基于外部供应修复剂系统的原理,使用预埋玻璃管向水泥基体中通入0.5 mol/L和0.1 mol/L两个不同浓度的NaH2PO4溶液,与水泥裂缝周围基体中溶出的Ca2+发生反应,原位生成磷酸钙类矿物以修复裂缝。采用裂缝宽度观测仪对裂缝的表观修复效果进行评价,并通过XRD、Raman和SEM测试手段对修复产物的物相及形貌进行分析,同时研究了NH+4对修复产物种类的影响。结果表明,磷酸盐溶液可修复宽度为200μm的裂缝,修复产物为羟基磷灰石、磷酸八钙和二水合磷酸氢钙。NH+4的加入促使修复产物中的二水合磷酸氢钙和磷酸八钙向稳定性更好的羟基磷灰石转化。

Based on the principle of external supply healing agent system,two different concentrations of NaH2PO4 solution of 0.5 mol/L and 0.1 mol/L were introduced into the cement matrix by glass tube to reacted with Ca2+dissolved from the matrix around the crack.Calcium phosphate minerals were formed to fill the crack.The visual healing effect was evaluated by crack width observer.The phase assemblage and morphology of healing products were characterized by XRD,Raman and SEM.The effects of NH+4 on the type of the healing products were studied.The results show that the phosphate solution can heal cracks with a width of about 200μm,and the healing products are hydroxyapatite,octacalcium phosphate and dicalcium phosphate dihydrate.The addition of NH+4 promotes the conversion of dicalcium phosphate dihydrate and octacalcium phosphate to the more stable hydroxyapatite in the healing product.