Research On Construction Quality Control And Evaluation Of Asphalt Pavement Based On Density Measurement

With the gradual promotion of the comprehensive quality management of asphalt pavement construction and paid according to the quality,the destructive tests will transform to the non-destructive one,and the evaluation method gradually changes from the basically satisfied quality standard to the excellently qualified grade standard.At present,the quality control method of asphalt pavement surface in China is confined to the sampling inspection of qualified judgment,which has caused a certain degree of damage to the road surface.The time-consuming and laborious samples are extremely limited,which can not reflect the uniformity of construction quality.The uniformity of road surface construction is an important control index for the evaluation of pavement quality.The variation of surface layer density of the construction section reflects the quality of pavement construction.Pavement Quality Indicator in non-destructive testing is an ideal detection tool to realize large sample,high frequency and timely and accurate measurement for surface layer density.This paper combines the process control and the dynamic quality management.With the large sample density's detection data(measuring point spacing 0.25m)of the middle surface course of several new asphalt pavements from Pavement Quality Indicator(PQI 380),based on the ??????? test and interval estimation in mathematical statistics,the qualitative comparison of the gray image and the quantitative evaluation of the weak regional segregation degree,the minimum effective detection frequency of the construction uniformity quality evaluation is finally determined.And the compaction quality control based on the density measurement during the road construction process,the optimal compaction scheme is determined by the curve relation between the rolling count and the measured density.The evaluation criteria and indexes of lateral and longitudinal construction segregation of asphalt pavement are established by the consistent analysis of comparison test method.At the same time,the lateral and longitudinal construction uniformity of each section are analyzed by intuitionally comparing the low and high frequency voids distribution generated by MATLAB.And the criterion of the degree of segregation of the middle surface course is established based on the statistical results of the interval voids ratio of each section.The average segregation evaluation index of the asphalt pavement is the weighted percentage of AREA,and the index is used to compare the whole construction uniformity effect of each section.And according to voids grayscale image of the rough and fine segregation,the apparent weak areas are directly visualized.The lateral and longitudinal directions of the weak areas are represented quantitatively by the coordinate method.In addition,based on the asphalt medium method,the experimental data of the Marshall specimen theoretical maximum relative density of several different asphalt materials and gradation type asphalt mixes were determined.The gray relative correlation method is used to determine the degree of influence of various factors on theoretical maximum relative density of the asphalt mixture,thus guiding the production of asphalt mixture and construction quality control,as well as to provide the direction for the correction of the weak area voids.