The Performance Evaluation Of The Old Road Semi-Rigid Base

As the main load-bearing layer, how to detect the semi-rigid base structure disease and evaluate its performance is very importent, at the same time,in recent years it has become a widly studied issue in the international road sector. Domestic methods currently used are measuring pavement deflectionto evaluate its performance with empirical model, however, this approach can not theoretically explain the relationship between the conditions of pavement force and diseases. Meanwhile surface deflection is a comprehensive index with a number of influencing factors, it is so difficult to distinguish their impact of each structural layers that accurate assessment of the performance of semi-rigid base will be impossible.Thereforea semi-disease evaluation method based on the disease analysis is proposedon the basis of previousresearch after further exploration and research.First of all, this paper introduces the present status of old road testing, maintenance and repair, analyzes the domestic and foreign current basic evaluation method and principle of semi-rigid base, introduces the domestic scholars research situation in the performance evaluation of the semi-rigid base, put forward the research contentin this paper. Through literature research about the disease of semi rigid base at home and abroad, the diseases of old road semi-rigid base has been divided into two parts of cracks and loose,and broken down for each kind of disease, It is the basis of the articles behind.Secondly, in view of the cracks diseases, from transverse crack, longitudinal crack, and vertical and horizontal cross stitchto simulate by using the finite element software ABAQUS, based on right table top compressive stress, deflection, asphalt layer of asphalt layer bottom stress, asphalt surface shear stress and tensile stress of the bottom of the semi-rigid base layer analysis, the evaluation characteristic value is determinedin view of the semi-rigid base crack defect evaluation index. From two aspects of global loose, local loose are simulated with finite element software ABAQUS to loose disease, through each structural layer of pavement stress and strain analysis, put forward the evaluation index and the eigenvalue of loose disease.Finally, the current of all kinds of detection methods are summarized, the advantages and disadvantages of damage detection methods and practicability are analyzed through the pavement core experiment. For all kinds of nondestructive testing method, The Ground Penetrating Radar (GPR) is focused introduced about the level status of cracks and loose detection of the semi-rigid base,the Ground Penetrating Radar (GPR) method is determinedto test performance scheme of semi-rigid base.A semi-rigid base performance evaluation method based on diseaseanalysis is put forward at last.