Study Of Rapid Thin Layer Reparation Technique For Cement Concrete Pavement

If the cement concrete pavement is repaird in time when it is in the early stage of damage, not only service life of the pavement can been prolonged, but also the maintenance cost of the project been decreased greatly. The thesis mainly studies the early and rapid repairing technique of the cement concrete pavement from the aspects such as patching structures and patching materials, in order to guide the maintenance project.For the thin layer of the cement concrete pavement , the design methods ,the design contents and the construction requirements of the patching materials are explained, and the characteristics of thin patching materials are intruduced. Starting from analysing the failure causes of bonding interface between fresh-old concrete, the resolutions of decreasing shrinkage strain are proposed. Shear stresses resulting from the vehicle load are calculated using the ANSYS finite element software to provide reference for engineering design. For shear strength of new-to-old concrete interface bond, the microscopic mechanism and the macroscopic mechanism are analyzed. The factors which effect the shear strength of interface are summarized, such as old concrete strength, surface roughness, the new-to-old concrete strength and the interfacial binder types etc. Some measures of improving the shear strength of new-to-old concrete bond interface are established. In laboratory, the shrinkage strain in thin layer of concrete slab are measured by the shrinkage strain experiment of concrete slab. The relationship models are obtained between the shrinkage strain of concrete pavement slab and composing materials and slab size. The calculation formula are proposed of several of shrinkage strain in the different size of concrete pavement slab. Based on the shear strength experiment, the relationships are found between the shear strength of new-to-old concrete interface and interfacial treatment, and the old concrete surface roughness. The range of the best optimal roughness , the best interfacial binder type and the mix proportion are recommended.The thesis perfects the overlay repair technique of cement concrete pavement based on the experiment research, and summarizes the thin layer repair mechanism of cement concrete pavement, design method, key points of construction technology and quality control measures.