Research On Construction Quality Control And Evaluation Of Asphalt Pavement Based On Non-uniformity

The premature failure of highway asphalt pavement in our country is especially serious in recent years. It can be found from a mass of investigation that the varying degree ununiformity exists in the asphalt pavement which has premature failure. Ununiformity is the significant reason that causes these premature failures in the area.In the asphalt pavement construction process, the timely and effective construction ununiformity control is effective to ensure the construction quality and service life, this paper puts forward a set of pavement construction heterogeneity controlling and evaluation standards. Through the PQI non-uniformity detection in field, combined with the inspection of the gradation variability on mixing plant, the reason of ununiformity can be intuitive analyzed by the universal volumetric chart. By researching on the relationship between the densities and temperature segregation, weak compaction as well as gradation segregation, the ununiformity controlling method can be raised in asphalt pavement construction. Combined the performance tests and image parameter analysis on the core samples about the different pavement density state, the pavement ununiformity evaluation standard has been proposed. The research achievement is of great significance for improving the asphalt pavement ununiformity, relieving the asphalt pavement premature failures, prolonging the service life of pavement, as well as building the resource-conserving highwayAccording to the law of time and space, the pavement construction ununiformity is divided into three stages in this paper, which contains the quality control (QC) of production variability in mixing plant, the QC and the quality valuation of construction ununiformity in field.First of all, aim at the variability in the mixing proportion, It is proposed to use the conventional control chart For dynamic control mixture production. Meanwhile, for the aggregate segregation on production, through the analyzing the correlation between average segregation rate, gradation difference, coarse aggregate ratio and coarse portion of fine aggregate in Bailey method, as well as fractal dimension and traditional segregation, and puts forward the average segregation rate as gradation control index.Secondly, in accordance with the study of the ununiformity matter in asphalt pavement construction, this paper analyzes the control processes of the three segregation types which contain the temperature segregation, weak compaction and gradation segregation, on the basis, combined the density detecting by PQI with the mixing proportion in asphalt mixing floor, the reasons of ununiformity is confirmed by using the universal volumetric chart. And the control standards of the temperature of segregation compaction as well as gradation segregation are proposed. Through the comprehensive analysis the key control index of heterogeneity is concluded.Thirdly, combining pavement density detected by PQI with the high and low temperature performance evaluated by pavement core samples tests and the segregation condition determined by the digital image technology, this paper proposes the respective evaluation index, and this paper also establishes the evaluating standard of asphalt pavement ununiformity, which is based on performance and image parameters.