【摘要】 对临沂市莒南县砂岩进行经历25~850℃高温作用后的力学试验。结合扫描电镜技术对高温作用后砂岩试样的物理力学性质和微观结构的变化规律进行观察。研究表明:砂岩的峰值强度在25~400℃间存在一定的波动,但整体上变化不大;在400℃以后,试样的峰值强度开始迅速下降;砂岩试样的变形位移总体上随处理温度升高而增大,在400℃以前变化不大,当温度高于400℃后峰值强度对应的位移迅速增加。扫描电镜图片显示当加热温度越高时砂岩微观孔隙越多,特别是在500℃时,部分颗粒胶结物已经遭受破坏。更多还原

【Abstract】 In this study,we conducted a number of mechanical experiments on sandstone samples from Junan County,Linyi City,in order to investigate the mechanical properties of the sandstone samples after being subjected to high temperatures,ranging from 25℃to 850℃.We plotted the peak strength and deformation displacement curves of the sandstone samples,based on the results of the uniaxial stress experiments under different temperatures.We observed the changes and differences in the sample microstructures after different temperatures using scanning electron microscope(SEM)technology.The results of the sandstone samples’ uniaxial stress tests are as follows:(1)At temperatures between 25℃and 400℃,the peak strength of the sandstone samples appears to fluctuate,but the overall strength changes only slightly.This means that the samples share the same mechanical properties,and the strength of the samples under these temperatures is steady.(2)When the temperature is higher than 400 ℃,the peak strength of the sandstone samples begins to decline rapidly.(3)With increasing temperature,the overall deformation displacement of the sandstone samples increases as well,growing very slowly,but increasingly,when the temperature is higher than 400 ℃.In addition,the SEM images show that the pores and fissures of the sandstone samples sharply increase when temperature reaches400 ℃.Cement particles in the samples begin to disappear when the temperature reaches 500 ℃.The study shows that the macroscopic mechanical properties of sandstone change radically at high temperatures.更多还原