腐蚀砂浆锚固体形貌特征及分形维数

Mortar anchor solid's corrosion morphology characteristics and fractal dimension

在砂浆锚固体腐蚀物理实验过程中所获得扫描电子显微镜(SEM)图像的基础上,通过图像处理技术提取了砂浆锚固体微观形貌特征,利用分形理论对形貌特征进行了定量描述,并建立了分形维数和砂浆锚固体的宏观粘结强度之间的关系,最后进行压汞试验,并与SEM图像处理的结果作对比分析。结果表明:随着腐蚀时间的增加,受力工况和未受力工况下锚固体的孔隙率均成线性增大,孔隙数量逐渐减少,孔隙的分形维数逐渐降低,分形维数和孔隙率成负线性关系;随着分形维数的减小,砂浆锚固体的粘结强度先增大后减小。压汞试验的测试结果与图像处理的结果对比,发现误差在5%~7%范围内。

Based on the scanning electron microscope（SEM）images taken from the mortar anchor corrosion experiment,we extracted the mortar anchors＇ microscopic morphology characteristics by image processing technology first,and quantitatively described the morphology characteristics by fractal theory.Then the relationship between the fractal dimension and the macroscopic bond strength of mortar anchor was established.Finally,the mercury intrusion test was applied to analyze the results of SEM image processing.The results show that,as the corrosion time gets longer,the anchor＇s porosities under both force conditions and non-force conditions linearly increase,but the pore number and the pore fractal dimension gradually reduce,and the relationship between fractal dimension and porosity is almost negatively linear.As the fractal dimension decreases,the bond strength of mortar anchor increases first,and then decreases.The results comparison of mercury intrusion test and the image processing shows thatthe inaccuracy is within the range of 5% to 7%.