The Experiment And Applied Research On Fiber Reinforced And Polymer Modified Cement Based Grouting Material

With the ever-growing highway mileage,the mode of "Comprehensive Maintenance" is being formed gradually.Grouting treatment is the common countermeasure of cement pavement maintenance.What's more,the material is the critical factor affecting grouting effectiveness.However,the existing grouting materials cannot meet the demand for highway maintenance.In order to develop a grouting material with high early strength,good toughness,easy access to raw materials and low cost,in this thesis,the experimental and applied study on fiber reinforced and polymer modified cement based grouting material is conducted,based on the methods of theoretical investigation,indoor testing,and engineering application.The major content and conclusions of this thesis include:(1)The characteristics of each component of the new grouting material are analyzed and the action mechanism of fiber and polymer on cement is introduced in detail.The types of cement,fiber and polymer in the new grouting material are preliminarily determined,which provided the theoretical basis for the laboratory tests.(2)Based on the laboratory tests,the effects of each component on the properties of the grouting material are studied,and then some key factors of the new grouting material,including the types of fibers,the fiber content,the ratio of Poland cement to sulpho-aluminate cement,the content of VAE emulsion,and the water cement ratio are determined.PVA fiber with the length of 6mm is chosen as the fiber reinforced material and its content is controlled in the range of 0.8?10%.The mass ratio of the sulpho-aluminate cement to the Portland cement should be controlled within the range of 0.5?1.1.The mass ratio of the VAE emulsion to the cement should be controlled within the range of 0.1?0.3.(3)Based on the study of the properties of the grouting material,the optimum proportioning test of fiber reinforced and polymer modified cement based grouting material is carried out.The optimal proportion of the new grouting material is determined.It means that the water cement ratio is 0.6,the content of VAE emulsion is about 2%of the cement by mass,the fiber content is about 1%of the pulp by volume,the fiber length is 6mm,and the mass ratio of sulpho-aluminate cement and Portland cement is 0.9:1.At the same time,the performance of the new grouting material and the traditional Portland cement grouting material is compared,which proved the advantages of the new grouting material.(4)Relying on the engineering project for treating the voids under the pavement slab on expressway,the field grouting experiment is conducted based on the Intelligent Control System.The effect of the new grouting material in practice is verified by the field test,and the grouting construction scheme for the new grouting material is determined.At the same time,through the experiment and applied research on the new grouting material,the study in this thesis has an important role in improving the quality of highway,and has created a great social and economic benefits.