| In order to systematically study the stable repair of the slope of the gangue hill drainage field and to lay the foundation for the next step of"green regeneration"in the mine area,the green all-waste concrete slope protection skeleton material is prepared by equal volume mixing of specific coal gangue in the mine area,the coal kaolinite which exists in the coal seam and the junction of the coal seam and the rock layer and the coal gangue which exists in the coal seam and the junction of the coal seam and the rock layer are used as coarse aggregate.The coal gangue present in the coal seam and at the junction of the coal seam and the rock seam is used as coarse aggregate,and the slope skeleton material is prepared by mixing the coal gangue and coal kaolinite with different blends in different volumes through local material extraction in layers.The macroscopic mechanical properties of the concrete material are analyzed through the concrete compressive strength test and splitting tensile strength test;the most accessible pore size,open porosity and NMR,NMR microscopic analysis are used in the preliminary stage,and the change law of porosity and pore radius size on the compressive strength value and internal crack change law are analyzed through GM（1,3）model and coal gangue solid waste-based concrete plastic damage model;the simulation of winter Climate,the use of rapid freeze-thaw machine,the determination of its concrete surface and microscopic by freeze-thaw damage deterioration and microscopic NMR pore by freeze-thaw deterioration law analysis;the use of dry and wet cycle machine,simulation of the Wuhai area,high temperature and rainwater environment under the coal gangue solid waste-based concrete damage situation.Exploration of coal gangue solid waste-based concrete material by erosion under the dry and wet cycle of its durable deterioration characteristics and its law;analysis shows that the new coal gangue solid waste-based concrete slope skeleton material（CGSBC）is feasible,comprehensive restoration of the environment,cost savings,expansion of the use of area has some significance.The slope skeleton material prepared in this study will be coal kaolin as coarse aggregate for large admixture,the coal gangue coarse aggregate for small admixture,so as to prepare an effective and suitable slope skeleton material,its toughness improved,strength in line with,play a"complementary and mutually beneficial"role,withstand durability deterioration damage,to meet its specification requirements,the main conclusions reached in this study are as follows.（1）CGSBC specimens with the increase of coal gangue coarse aggregate admixture,the overall compressive strength of coal gangue concrete is gradually reduced,coal gangue concrete toughness presents the trend of first increase and then decrease,but the mechanical strength are in line with the requirements of the slope skeleton material;internal pores mainly present"three peaks"structure.With the increase of coal gangue substitution rate,the internal tiny pore ratio of CGSBC specimen increases,medium and large pores decrease and porosity increase;small amount of coal gangue mixture that can meet the mechanical strength requirements and can be superior to the internal pores of CGSBC specimen.（2）CGSBC specimens real data and ash entropy correlation analysis（1.3）model prediction and experimental value of the average error of 3.69%,so that the GM（1.3）model for coal gangue solid waste-based concrete has a certain predictability,can be predicted through different sequences of data on its porosity,pore radius on the compressive strength value;the use of concrete plastic damage fine view model,with a certain reliability,can effectively describe the damage damage process and morphology,and the fracture characteristics are consistent with the test.（3）CGSBC specimens subjected to freeze-thaw cycles,with the increase in the amount of gangue,the gangue itself acicular,low strength,micro powder and other characteristics of the gangue"cavity"phenomenon resulting in the increase in internal frost stress of concrete,the signal amplitude and peak of the T2 spectrum increased significantly,and the initial relaxation time increased significantly,the increase in pore space;gangue absorption rate is high,the concrete specimen internal free water by freezing and melting,will cause damage to the internal pore structure,pore size increases;small pores to medium pores,medium pores to large pores,large pores to larger pores,concrete deterioration,aggregate stripping serious,change the concrete stress state,further affect the form of damage and destabilization process.（4）CGSBC specimens under sulphate erosion,with the increase in the number of wet and dry cycles,corrosion resistance coefficient decline rate accelerates,the mass loss rate and relative dynamic elastic modulus loss show a trend of first increase and then decrease;erosion products can play a dense role to delay the decay of the mechanical properties of concrete in the early stage,but in the later stage of concrete,due to internal erosion damage,resulting in more weak areas in the concrete,thus In the later stages of concrete,however,the erosion damage within the concrete results in more weak zones,thus creating concentrated stresses in different parts of the compressive process,thus accelerating the decay of the mechanical properties of concrete in the later stages.With the increasing number of erosion,the second and third peak areas are expanding,gradually shift to the right,the pore size gradually increases,the signal amplitude and peak of the T2 spectrum increases significantly,and makes the initial relaxation time increases significantly,the pores increase,small pores to medium pores,medium pores to large pores,large pores to larger pores,the internal gradually deteriorate and be destroyed;the increase of gangue admixture,the internal Coal gangue pore structure and surface will be more than coal kaolinite first damage,cracks,will greatly lead to coal gangue its internal damage damage,by the internal damage occurred first,prompting the rate of deterioration of the specimen increase.（5）the addition of fly ash to delay the cement hydration process,the growth of cementitious material hydration set hardening time interval,the formation of effective step hardening trend,so that the interface transition zone and the gangue internal pore characteristics have been improved,optimize the gangue and slurry interface bonding ability,improve the internal structure of CGSBC specimens,weaken the freeze-thaw cycle generated by the expansion as well as permeability and erosion under the dry and wet cycle generated Erosion products destroy the internal rate of concrete,reduce the amount of cement,improve the internal compactness of concrete,and effectively improve the strength development and impermeability of concrete. |
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