Research On Road Use Technology Of Industrial Waste Residue Red Mud

In order to study the related properties of industrial waste slag and red mud as road materials,this thesis analyzes the physical and chemical properties of red mud and waste slag,and studies the direct use of red mud as a filler for filling roadbeds,and the use of cement to solidify the red mud as a road subbase,and use part of the red mud instead of cement to make cement red mud concrete curbs,and study it's corresponding strength formation mechanism.The analysis of the physical and chemical properties of red mud shows that the main chemical composition of red mud is SiO₂ and CaO,followed by a small amount of Al₂O₃and Fe₂O₃.The main mineral components of red mud are cancrinite,hydrocalumite,diaspore,magnesia,hematite,etc.,as well as a small amount of titanium minerals and other minerals.The red mud has irregular particle shape and finer particles.The specific gravity is slightly larger than that of ordinary soil,with strong water richness and high moisture content.It is hard and plastic under natural conditions,and it's properties are close to silty clay.Research on the physical and mechanical parameters of red mud shows that the optimal moisture content of undisturbed red mud is 29.6%and the maximum dry density is 1.48 g/cm³.The CBR value of the red mud is the largest under the optimum moisture content and the maximum compaction times,which can reach about 13.The change of the modulus of resilience is similar to the CBR value.When the water content increases,the shear stress of the red mud increases first and then decreases.The internal friction angle of the red mud under the optimal water content state is 35.85°,and the cohesive force is 104.33k Pa.In the process of increasing the filling height of the red mud roadbed from 3m to10m,the slope stability coefficient k decreased from about 13 to about 5.The stability coefficient of the red mud roadbed slope was higher than that of the general roadbed filling.The coefficient of performance indicates that the stability of the slope with red mud used as subgrade filling has a good guarantee.The settlement deformation of the red mud roadbed mainly occurs in the first 5 years after the completion of filling,and it tends to be stable in the later period,and the overall resistance to settlement deformation is excellent.When researching cement stabilized red mud mixture as pavement structure layer,the cement mixing ratio used in this thesis is 4%,6%,8%,10%and 12%of the dry weight of red mud.The research results show that the optimal moisture content of the red mud after adding cement gradually increases,while the maximum dry density decreases slightly;the strength of the red mud after adding cement is significantly increased,and the 7-day immersion strength of the cement stabilized red mud mixture is all above 1MPa,it meets the technical specification requirements of the high-grade pavement for the base layer,and the resilience modulus and splitting strength are consistent with the change law of the compressive strength,and fully meets the requirements of the high-grade pavement for the base layer.The cement stabilized red mud has good frost resistance and the shrinkage rate also meets the requirements.When the cement content exceeds 10%,it's strength will not increase significantly,so the optimal cement content should be controlled between 8%and 10%.Research on the application technology of cement red mud concrete curbs found that the appearance and size deviation of cement red mud concrete curbs meet the requirements of the specification,and the specimens are more beautiful overall.Use ground red mud to replace part of the cement.When the amount of fine red mud to replace the cement is more appropriate,satisfactory strength can be obtained,especially for the flexural strength of the curb.The water absorption and resistance of the concrete curb the freezing property changes slightly with the change of the red mud content,but the overall performance is better and meets the specification requirements.However,when the ratio of red mud to replace cement reaches 30%,the compressive and flexural properties of cement red mud concrete will be significantly reduced.Therefore,in order to ensure that the performance of the cement red mud concrete curb can meet the specification requirements,it is required to the amount of mud instead of cement shall not exceed 30%.Research and analysis on the mechanism of cement red mud found that cement stabilized red mud base layer uses cement as a stabilizing material to form a slab after rolling.The main mechanism of action is the hydration reaction of cement.Cement stimulates the activity of red mud,makes the red mud participate in the reaction,and enhances the degree of hydration reaction.The action mechanism of cement red mud concrete is mainly the addition of red mud,which promotes the hydration of cement or the red mud also undergoes a hydraulic gelation reaction similar to cement.