遇水快速冷却与自然冷却对高温花岗岩物理性质影响实验研究

Experimental study on the influence of rapid water cooling and natural cooling on the physical properties of high temperature granite

干热岩开发、火灾后重建等高温岩石工程中,高温状态下的花岗岩会受到水的快速冷却作用。本文通过对实验组花岗岩(高温—遇水冷却试验)与对照组花岗岩(高温—自然冷却试验)物理性质的对比分析,揭示了遇水冷却与自然冷却这两种冷却方式对花岗岩物理性质的影响及其差异。主要结论如下:随温度升高,两组花岗岩均由灰白色逐渐转变为红棕色,自然冷却条件下的花岗岩红棕色更明显;两组花岗岩质量降低率均随加热温度的升高而增长,各温度点遇水冷却条件下的岩石质量损失率更低;两组花岗岩体积增长率的阈值温度为400℃,各温度点遇水冷却条件下的岩石体积增长率更高;两组花岗岩纵波速度与横波速度均随加热温度升高呈线性降低,遇水快速冷却条件下波速的损伤较自然冷却条件下小。

In high temperature rock engineering such as the dry hot rock development and the post fire reconstruction, the granite after high temperature will be rapidly cooled by water. In this paper, the physical properties of the granite in the experimental group ( high temperature heating-water cooling tests) and the matched group of granite ( high temperature heating-natural cooling tests) are compared and analyzed. The effects and difference of the two different cooling methods on the physical properties of the granite are revealed. The main conclusions are as follows: with the increase of temperature, the two groups of granite gradually change from gray to reddish brown , and the granite red brown under natural cooling condition is more obvious;the mass reduction rate of the two groups of granite increases with the increase of heating temperature, and the rock mass loss rate at different temperatures is lower under water cooling condition;the threshold temperature of volume growth rate of the two groups of granite is 400^, and the volume growth rate of rock under water cooling condition is higher at each temperature point;the longitudinal wave velocity and shear wave velocity of the two groups decrease linearly with the increase of heating temperature, and the damage of wave velocity under water fast cooling condition is smaller than that under natural cooling.