对20℃、70℃、140℃、200℃、300℃、400℃、600℃、800℃等8种不同温度后红砂岩的力学特性进行了试验研究，结合压汞、SEM扫描电镜微观试验分析不同温度后红砂岩孔隙结构变化及微裂纹产生规律，并对红砂岩的不同温度劣化微观机制作初步探讨。研究表明：（1）不同温度后红砂岩单轴抗压强度在300℃达到峰值为常温的1.4倍；红砂岩劣化阀值温度为600℃，单轴抗压强度降幅达32.5%；（2）不同温度后红砂岩产生的裂纹宽度绝对多数分布在0～0.01 μm区间内，该区间内各阶段裂缝的分布比值与单轴抗压强度呈较好的相关性；（3）沿晶和穿晶裂纹产生以及裂纹均质性变差是红砂岩劣化的主要影响因素。

Researches are carried out on the mechanical properties of red sandstones treated at 20 °C, 70 °C, 140 °C、200 °C, 300 °C, 400 °C, 600 °C and 800 °C, respectively. Based on the researches, the regular patterns of the pore structure and micro fracture of the heated red sandstones are investigated combined with mercury and scanning electron microscope analyses. It is concluded that: (1) the maximum uniaxial compressive strength of heated red sandstones at 300 °C is 1.4 times as much as that of red sandstones at room temperature. The uniaxial compressive strength decreases by 32.5% when red stones are heated to 600 °C. (2) The crack widths of heated red sandstones are mainly ranged from 0 to 0.01 μm, during which there are better correlation between the distribution ratio of cracks and the uniaxial compressive strength. (3) The main affecting factors of the deterioration of red sandstones are the transgranular cracks and heterogeneity of cracks.