Mineral Powder And Fly Ash Grouting Material Test And Pavement Base Layer Grouting Reinforcement Research

Under the influence of vehicle load and natural factors,pavement damage occurs,producing cracks,potholes,rutting,etc.In the long run,the pavement subgrade is loosened and damaged,and the bearing capacity of the pavement structure is reduced,which affects the traffic safety and the life of the road.Grouting technology is to inject slurry into the pavement base or roadbed through drilling,which can strengthen the base and improve the load-bearing capacity.With the development of industry,a large amount of industrial waste slag such as fly ash and slag is produced,which causes pollution to air and water resources.By stimulating the activity of waste slag can form cementitious material and replace cement,reduce CO₂emission when producing cement,reduce environmental pollution,and make secondary use of industrial waste slag.In this thesis,a grouting material with early strength and good flowability was formulated through workability,mechanical properties and durability material tests to optimize the matching ratio.The core samples of the pavement were drilled and analyzed by uniaxial compressive test,splitting strength test and void rate determination:（1）Based on the existing research grouting materials as well as theories,the range of mineral powder and fly ash substitution for sulfuric acid cement dosing as well as the water reducing agent dosing were determined by indoor single-factor tests.Mineral powder,fly ash,bentonite and water-cement ratio were used as factors,and the optimum dosing of each factor was obtained by orthogonal test with extreme difference and analysis of variance.On the basis of this,the alkali exciter was added,and the freezing resistance and sulfate resistance were improved by the setting time,flow rate,compressive test,flexural test,dry shrinkage test,freeze-thaw test and sulfate resistance test.The modulus of exciter was determined to be 1.25,and the dosing of alkali exciter was 10%.（2）Uniaxial compressive test,splitting test and void rate determination were performed by taking cores from each lane lesion at the site.The compressive resilient modulus strength and splitting strength of the core samples were lower than the recommended values of4.96%～20.83%and 10%～20%respectively.The void rate of core samples at cracks was higher than the design value of void rate,and the core samples at rutting were diseased lower than the design value of void rate.（3）Grouting reinforcement technology was used to reinforce the grass-roots level at cracks and rutting lesions,and the change in bending and settlement before and after grouting was analyzed by bending and settlement values,combined with radar detection to analyze the change in images before and after,and cores were taken for splitting tests.The degree of repair of the two types of highway diseases was analyzed,and some reference was provided for the repair of these two types of diseases.It can be seen that the bending settlement after grouting is reduced to within 1.4 times of the original pavement bending settlement value,and the splitting evaluation strength of its core base is increased by25.08%.