This study is an investigation of the effect of high temperatures on the engineering properties of sandstone. The rock was first subjected to a range of temperatures such as 25 °C, 200 °C, 400 °C, 600 °C and 800 °C, and a series of porosity, unconfined compression, X-ray diffraction and scanning electron microscope tests were then performed on the heated specimens. In addition, sandstone specimens were also subjected to different numbers (i.e. 1, 2, 4, 6 and 10) of thermal cycles to better understand the effect of high temperature variations on rock behaviour. It was observed that high temperature in the range of 200–400 °C had some influence on the rock properties; that is, the porosity slightly decreased while the strength of the rock increased. However, for T ≥ 600 °C, there was a significant increase in rock porosity that correlated with a decrease in rock strength. The observed changes in engineering properties were attributed to the changes in rock mineralogy and microstructure that occurred at T > 600 °C where the major minerals underwent the process of phase transformation and a significant increase in rock cracking. Regardless of the temperature, almost all specimens failed in tension during unconfined compression. The effect of thermal cycles was seen in a progressive increase in rock porosity and a corresponding decrease in the elastic modulus of the rock.

这项研究是研究高温对砂岩工程特性的影响。首先对岩石进行一系列温度测试，例如25°C，200°C，400°C，600°C和800°C，并进行一系列孔隙度，无边压缩，X射线衍射和扫描电子显微镜测试然后在加热的样品上进行。此外，砂岩标本还经历了不同数量（即1、2、4、6和10）的热循环，以更好地了解高温变化对岩石行为的影响。观察到200-400°C的高温对岩石特性有一定的影响。也就是说，孔隙率略有下降，而岩石的强度却增加了。但是，对于T≥600°C，岩石孔隙度显着增加，与岩石强度降低相关。观察到的工程性质变化归因于T> 600°C时岩石矿物学和微观结构的变化，其中主要矿物经历了相变过程，并且岩石开裂显着增加。无论温度如何，几乎所有样本在无限制压缩过程中都无法拉伸。在岩石孔隙度逐渐增加和岩石弹性模量相应降低的情况下，可以看到热循环的影响。600°C，主要矿物经历相变过程，岩石开裂显着增加。无论温度如何，几乎所有样本在无限制压缩过程中都无法拉伸。在岩石孔隙度逐渐增加和岩石弹性模量相应降低的情况下，可以看到热循环的影响。600°C，主要矿物经历相变过程，岩石开裂显着增加。无论温度如何，几乎所有样本在无限制压缩过程中都无法拉伸。在岩石孔隙度逐渐增加和岩石弹性模量相应降低的情况下，可以看到热循环的影响。