高温水冷后花岗岩微观孔径及渗透性分析

高温热处理后岩石的物理力学性质的变化与其内部孔隙结构的改变有关.以高温水冷处理后的两种花岗岩为研究对象,进行了气体渗透试验,研究了其渗透性随温度的演化规律及微观孔隙结构的变化,并利用比表面积及孔径分析测试从微观层面分析了高温水冷处理后花岗岩的损伤演化和裂隙发育机理,为宏观物理性质改变提供了理论依据.结果表明,两种不同的花岗岩在受到高温水冷后表现出相同的规律,随着温度的升高,岩石内部逐渐产生温度裂隙,比表面积增大、总孔体积增大.利用比表面积及孔径分析得到了岩石内部纳米级孔隙的分布情况,发现在温度的作用下岩石内部的介孔受温度的影响最大.可见,在高温热处理后花岗岩内部的温度裂隙是影响岩石物理性质的主要因素之一,同时利用比表面积及孔径分析测试可以得到花岗岩内部的纳米级孔隙分布情况,为花岗岩的微观孔隙结构研究提供了技术支持.

Analysis of microscopic pore size and transfer properties of granite after heating and water cooling treatment

The variation of physical and mechanical properties of rock after heat treatment is related to the variation of internal pore structure. In this paper, two kinds of granites treated with heating and water cooling treatment were taken as the object. Gas permeability test was carried out to study the evolution of transfer properties and changes in microscopic pore structure. The specific surface area and pore size analysis tests were used to analyze the damage evolution and the crack development of granite after heating and water cooling treatment at a microscopic level which provides a theoretical basis at a macroscopic level. The results show that two granites with different compositions show the same rules after being subjected to high temperature and water cooling. As the temperature increases, temperature cracks gradually occur inside the rock, physical properties decrease, specific surface area increases, and total pore volume increases. And the distribution of nano-scale pores in the rock can be obtained by using specific surface area and pore size analysis. It is found that the mesopores are most affected by temperature. It can be seen that the thermal cracks are one of the main factors affecting the physical properties of rocks. And specific surface area and pore size analysis tests can be used to obtain the nano-scale pore distribution inside the granite, which provides technical support for the study of the micro-pore structure of the granite.