Study On Radar Wave Propagation Mechanism And Utilization Of Ground Penetrating Radar In Asphalt Pavements

Traditional pavement detection methods destroy the structure and appearance of roads.And with continues increase of the mileage of the pavements,the traditional ways have been unable to meet the needs of road detection.Ground penetrating radar?GPR?attaches more importance as it can detect quickly and continually and plays a significant role in road evaluation.The relative theory and results of field testing,as well as utilization of GPR in thickness,compaction and moisture content detection of asphalt pavement are studied.Parameters of GPR device are analyzed according to principle of electromagnetic wave.Firstly,related formulas are deduced and systematic error are corrected using the IDS radar.According to superposition principle,the optimum detection height of the antenna is measured.The index V₍??6-??which affects the accuracy of the moisture content detection is proposed.What's more,an aqueous mixture model is proposed and successfully applied to the prediction of the dielectric constant of the mixture.Secondly,the finite element simulation of GPR is carried out.The model setting and boundary conditions of modeling in the frequency domain are studied.In addition,the difficulty of detecting the position of the disease inside the road is judged under transient conditions.The model with random gap and water content is established using Monte Carlo method and experiments are carried out to assess the effect of voids on the model.It was found that the void radius has a greater influence on the model than the void ratio.Finally,GPR is used to detect the internal diseases of the road surface.Starting from the GPR image,after denoising,segmentation and morphological processing of the radar image,the interlayer defects and pipelines inside the road surface are identified.The program is finally compiled into software.