Study On The Freezing Thawing Damage Characteristics Of Coal Gangue Two Ash Mixture Based On CT Scanning

As the base material of road,the coal gangue dui mixture is affected by freeze-thaw cycle in the process of road use,and its carrying capacity will be reduced.At present,the research data on the antifreeze performance of coal gangue mixture is relatively few,and the research materials on the characteristics of the permafrost damage are still not reported.Therefore,it is necessary to study the antifreeze performance of the coal gangue and the characteristics of the freezing and thawing damage.The main contents of this paper are as follows: first,the design of freeze-thaw test and the design of CT scanning test were carried out.The physical and chemical properties of raw materials in gangue two ash mixture were determined,and all indicators met the requirements of the specification.On the basis of measuring the optimum water content and maximum dry density of coal gangue two ash mixture,the change law of appearance,quality and frost resistance index of coal gangue two ash mixture after freezing thawing cycle was analyzed by freezing and thawing test.By analyzing the results of CT scanning test,the freeze-thaw damage variable was defined by digital image processing technology,and the freeze-thaw damage variables of different materials in different areas of coal gangue two ash mixture were calculated.The cross-sectional area damage rate of the specimen is calculated by image segmentation technology.The freeze-thaw damage characteristics of gangue two ash mixture were analyzed.The results show that the frost resistance index of coal gangue two ash mixture decreases linearly with the increase of freezing and thawing times in 15 freeze-thaw cycles,and the frost resistance of coal gangue two ash mixture is good.The damage degree of the two ash mixture of coal gangue is gradually reduced from the outside to the inside,from the outgoing area to the damaged area,the micro damage area and the micro damage attenuation area,and the micro damage caused by the freezing thawing damage mainly comes from the cementing material formed by the two ash.