岩石耐温抗冻性能室内试验分析

选取灰岩、砂岩、煤岩3种常见岩性作为试验对象，展开“常温（20 ℃）～-30 ℃”、“常温（20 ℃）～1 000 ℃”的低温、高温状态渐变温度室内试验，深入了解温变条件下不同岩石试件物理参数、热物理参数、单轴抗压强度参数的整体变化规律。结果表明：① 低温变化过程中，孔隙率越大，水分析出现象越明显，岩石热导率随着温度降低呈现先增大后减小现象，在-10 ℃达到峰值；而试样单轴抗压强度随着温度降低而逐渐增加；② 高温变化过程中，在达到某一阈值温度时，质量损失率明显提升；随着温度升高，热导率稳步降低，且与温度呈近似线性关系；试样单轴抗压强度随着温度升高而逐渐降低，且在达到特征温度后，其强度值明显降低；③ 岩石结构越致密，孔隙率越低，天然强度越大，其温度影响敏感性越低，耐温抗冻性能越佳。

Laboratory experimental analysis on performance of heat and frost resistance of three common rocks

In order to acquire the overall change rule of physical parameters,thermal physical parameters and uniaxial compressive strength of different rocks,three common rocks,that granite,sandstone and coal rock from are selected to carry out laboratory experiments with variable temperature including low temperature from 20 ℃ to -30 ℃ and high temperature from room temperature (20 ℃) to 1 000 ℃,and get the main conclusions as follows:① In the changing process within low temperature，phenomenon of water precipitation is more obvious under the condition of high porosity,and thermal conductivity of rock decreases after an increasing process,reaching its peak at -10 ℃,but the uniaxial compressive strength of rock sample increases gradually with the decreasing of temperature;② In the changing process within high temperature,the rate of mass loss increases significantly when the temperature reaches a certain threshold;With the increasing of temperature,the thermal conductivity decreases steadily and shows an approximate linear relationship with temperature;the strength of rock sample decreases gradually with the increasing of temperature,and reduces obviously when reaching its characteristic temperature;③ Rock with compact structure and low porosity has higher natural strength,lower sensitivity to temperature and better heat and frost resistant properties.