The change characteristics of meso-structure of marble are analyzed and studied under different temperature condition, the results show that the influence of temperature on marble microscopic structure are strong, combined with micro-photometer analysis. Marble minerals composite, meso configuration and the rock thermal cracking in differ temperature are observed by micro-photometer in meso. By means of experiment, Marble is composited by kinds of minerals, and its minerals' inhomogeneity is visible, the change of cementation among rock crystal grains, dislocation and micro cracking in crystal is produced in crystal grains under temperature. The development of marble micro cracks and interior configuration, and change law of micro cracks were observed. The quantitative analysis of the micro mechanism and laws of marble thermal crack was made, the development of micro cracks changes with regularity, marble cracks number increases acutely in 600–700 degree C after a narrow range fluctuation in 200 degree C. Finally, the thermal cracks threshold of marble was determined primarily.
Rock is a kind of polymer composed of different mineral particles or crystals together. Under thermal acting, its mechanical effect is that micro structure change lead to the change of macroscopic mechanical properties, in the meanwhihe, there will be obvious thermal cracking and other changes. The study has the economical benefit and the social significance. For example the coal underground gasification, and so on, to realize the globe inner configuration and study the mechanism of earthquake need researching and discussing the states and the laws of development of rock in high temperature.
Somerton researched the corrode change sandstone on the thermal effect and they discovered that the rock permeability increases 50% (Somerton et al. 1965). Chen yong discovered that the threshold of marble is 60°C–70°C for the Westerly marble, carbonate rock has a permeability threshold on the effect of temperature, the rate of filter will increase 8–10 times exceeding its threshold (Chen 2001). Yang ShengQi considered that the essence of rock rheological failure is due to comprehensive effect of defects and heterogeneity in material structure and microfissure long-term cumulative damage.
Homand-Etienne studied the crack formation of marble on the effect of temperature, discovered rock connectivity increasing and producing new cracks after heat treating (Homand et al. 1989).