摘要
The meso-structure mineral composition and fracture mechanism of uniaxial compressed mudstone samples at high temperature were analyzed by XRD and scanning electron microscopy. The effect of tem- perature on mudstone composition and fracture mechanism were studied from a meso-structural per- spective, and the relationship between meso-structure and macro-mechanical characteristics at high temperature was revealed. The findings demonstrated that the fluctuation in diffraction intensity of kao- linite in the mudstone caused the fluctuation in its mechanical properties. The overall structure under- went a phase change around 600℃, which led to the sudden change in the mechanical properties of mudstone samples. When the temperature reached 600 ℃, the crystalline state worsened and kaolinite disappeared; however, some illite was produced, indicating that the chemical reaction of the structure and sudden drop of bearing capacity of the mudstone. Mudst0ne fracturing at high temperature involves mainly intergranular and transgranular fractures, which are typical in micro-brittle tensile failure. Con- sidering the macro-fracture characteristics of mudstone, the results suggested that macro-fracture under external force corresoonds to the meso-fracture.
The meso-structure mineral composition and fracture mechanism of uniaxial compressed mudstone samples at high temperature were analyzed by XRD and scanning electron microscopy. The effect of temperature on mudstone composition and fracture mechanism were studied from a meso-structural perspective, and the relationship between meso-structure and macro-mechanical characteristics at high temperature was revealed. The findings demonstrated that the fluctuation in diffraction intensity of kaolinite in the mudstone caused the fluctuation in its mechanical properties. The overall structure underwent a phase change around 600 ℃, which led to the sudden change in the mechanical properties of mudstone samples. When the temperature reached 600 ℃, the crystalline state worsened and kaolinite disappeared; however, some illite was produced, indicating that the chemical reaction of the structure and sudden drop of bearing capacity of the mudstone. Mudstone fracturing at high temperature involves mainly intergranular and transgranular fractures, which are typical in micro-brittle tensile failure. Considering the macro-fracture characteristics of mudstone, the results suggested that macro-fracture under external force corresponds to the meso-fracture.
基金
financial support from the National Natural Science Foundation of China(Nos.51074166,51104128,51322401 and 51204159)
the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120095110013)
the Science and Technology Projects of Urban and Rural Housing Ministry of Construction of China(No.2011-k3-5)
the‘‘Blue Project’’of Jiangsu Province are greatly appreciated
