Real-Time Recognition Of Aggregate Morphology And Gradation During Pavement Construction Based On 3D Improved Area Growth

In pavement construction,the mixture is easy to appear different degrees of segregation due to transportation and paving.This will lead to the mixture after paving is prone to local area gradation inconsistent with the design gradation.Aggregate,as an important component of pavement materials,plays a decisive role in the performance of pavement with its morphological characteristics and gradation,which largely determines the mechanical properties and road performance of mixtures.Therefore,in order to ensure the performance of pavement mixture after construction,the gradation characteristics of pavement mixture after layering and paving should be monitored in real time.It is difficult to realize the real-time monitoring of aggregate morphology and grading characteristics in the process of pavement construction due to the lag of the traditional post-screening measure of aggregate gradation in laboratory by on-site sampling.Therefore,this paper will carry out real-time identification research on aggregate morphology and gradation in pavement construction process based on 3d improved area growth,in order to realize real-time monitoring of aggregate morphology and gradation in pavement construction process.The specific research contents are as follows:(1)Determine the image-based 3d model construction method and technical process for the surface of pavement loose paving,make smooth correction,tilt correction and proportion correction for the established model,realize the pre-processing of the model,and export the text file to provide a basis for subsequent data analysis;(2)In view of the shortcomings of the traditional aggregate grading detection method in the process of pavement construction,an improved region growth segmentation algorithm based on 3d point cloud reconstruction is proposed based on image processing technology to realize the recognition and separation of aggregate with feature points in the layered and paved mixture in the process of pavement construction.(3)Aggregate shape parameters are determined according to section information,and the equivalent sphere diameter is proposed as the basis for calculating aggregate gradation in the mixture.On this basis,a detection system of aggregate morphology and gradation in pavement construction process based on the growth of 3d improved region is developed to realize the real-time detection and adjustment of aggregate morphology and gradation in pavement construction process.Finally,combined with simulation experiment and field experiment based on three dimensional improved region growing process of pavement construction aggregate morphology and grading identification method,the experimental results show that:(1)local region growing image segmentation algorithm based on improved can accurately identify the road raised aggregate part in the construction of loose layer,and can be used in pavement construction in the process of paving surface aggregate form and graded monitoring;(2)As one of the criteria for evaluating aggregate particle size,the equivalent spherical particle size should be evaluated jointly with the cross-section morphological parameters.The final results of this study will provide technical support for the real-time monitoring of loose paving aggregate in the process of pavement construction.