The aim of this paper is to investigate the damage cracking characteristics of rock and soil aggregate(RSA)by X-ray computed tomography(CT)under uniaxial compressive loading.The mean CT value for the region of interes...The aim of this paper is to investigate the damage cracking characteristics of rock and soil aggregate(RSA)by X-ray computed tomography(CT)under uniaxial compressive loading.The mean CT value for the region of interest(ROI)is used to analyze the cracking characteristics.Also,the mathematical morphology method based on the image threshold segmentation is used to obtain characteristic parameters of cracks to describe the cracking evolution of RSA.Results show that the elastic mismatch between rock blocks and soil matrix is the primary reason for RSA cracking.The mean CT value for the RSA specimen,rock block inclusions,and their adjacent soil regions decreases with the increasing stress level.However,it is more sensitive for block inclusions than soil regions.Using the image segmentation method,length,area and mean width of cracks obey to power function distribution.Crack statistical characteristics are closely related to the rock block’s distribution and morphology.These results may be useful to reveal the mesoscopic cracking mechanism,establish meso-damage evolution equation,and constitutive relation for RSA.展开更多
The effects of petroleum sulphonate, HPAM and pH value on the zeta potential of Na-montmo-（rrillonite） suspensions were investigated, and orthogonal design of experiment was used to study the effect of these factors...The effects of petroleum sulphonate, HPAM and pH value on the zeta potential of Na-montmo-（rrillonite） suspensions were investigated, and orthogonal design of experiment was used to study the effect of these factors on the zeta potential of montmorillonite suspensions when the three factors existed simultaneously. The results show that the zeta potential of montmorillonite becomes more negative with the increase of the concentration of petroleum sulphonate, that of HPAM, and the pH value. Moreover, FpH=13.3(>F0.01=9.78), FHPAM=7.73(>F0.05=4.76) and Fpetroleum sulfonate=3.05 when the three factors co-exist, thus the effect of pH value on the zeta potential of montmorillonite is the most prominent factor, the HPAM a less prominent factor, and the petroleum sulphonate is least prominent.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.41227901,41027001,and 41027001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grants Nos.XDB10030000,XDB10030300 and XDB10050400)
文摘The aim of this paper is to investigate the damage cracking characteristics of rock and soil aggregate(RSA)by X-ray computed tomography(CT)under uniaxial compressive loading.The mean CT value for the region of interest(ROI)is used to analyze the cracking characteristics.Also,the mathematical morphology method based on the image threshold segmentation is used to obtain characteristic parameters of cracks to describe the cracking evolution of RSA.Results show that the elastic mismatch between rock blocks and soil matrix is the primary reason for RSA cracking.The mean CT value for the RSA specimen,rock block inclusions,and their adjacent soil regions decreases with the increasing stress level.However,it is more sensitive for block inclusions than soil regions.Using the image segmentation method,length,area and mean width of cracks obey to power function distribution.Crack statistical characteristics are closely related to the rock block’s distribution and morphology.These results may be useful to reveal the mesoscopic cracking mechanism,establish meso-damage evolution equation,and constitutive relation for RSA.
文摘The effects of petroleum sulphonate, HPAM and pH value on the zeta potential of Na-montmo-（rrillonite） suspensions were investigated, and orthogonal design of experiment was used to study the effect of these factors on the zeta potential of montmorillonite suspensions when the three factors existed simultaneously. The results show that the zeta potential of montmorillonite becomes more negative with the increase of the concentration of petroleum sulphonate, that of HPAM, and the pH value. Moreover, FpH=13.3(>F0.01=9.78), FHPAM=7.73(>F0.05=4.76) and Fpetroleum sulfonate=3.05 when the three factors co-exist, thus the effect of pH value on the zeta potential of montmorillonite is the most prominent factor, the HPAM a less prominent factor, and the petroleum sulphonate is least prominent.
