Impact Penetration Method To Detect Cement Concrete Pavement In The Shallow Strength

In the process of using, the cement concrete is affected by the environment and traffic load repeatedly. When the freezing disaster occurs, the function of cement concrete shallow pavement dropped sharply due to repeated freeze-thaw. Main characteristic is increases of porosity, reduce of the strength. Due to the existing evaluation method cannot effectively evaluate the reduction of shallow cement concrete pavement strength; this article puts forward the use of impact penetration method to detect the shallow strength. This paper first improve the penetration detector of shallow asphalt pavement strength, then study the rule of cement pavement impact penetration using the FEM, and finally the scale of hammer and penetrator are conformed by scene and laboratory test. Establish the relationship of cement pavement strength and penetration depth.First of all, the paper studies the applicability of the impact of penetration method to detection cement concrete pavement in shallow strength and the penetration resistance principle. And study the relevant impact instrument. And in this foundation, improve the penetration detector of shallow pavement strength. Design the penetrator and hammer fit for the cement concrete pavement.Then, in order to preliminary understanding instrument performance, and to provide reference for the test, this paper impacts the law of penetration using ABAQUS software in finite element simulation. Select the Concrete constitutive model applicable to the analysis of the impact -Concrete Damage Plasticity model. Then the impact simulation is taken using the constitutive parameters provided by ABAQUS. Then analyze the results of finite element simulation, compare the influence to the pavement between different hammer weight and different penetrator diameter.Finally, instrument performance and the rule of the penetrator by the field and laboratory test. In the field test, select the test that has different frozen damage strength characteristics, impact penetration test is taken using different hammer weight and penetrator diameter, analysis the performance of the instrument, determine the size of hammer and penetrator fit for cement concrete pavement. Then laboratory test is taken using the determined hammer and penetrator, design four group of testing with different strength, and two kind of shallow strength evaluation methods are analyzed, establish the test relationship between cement concrete pavement shallow strength and penetrating depth.