The Improvement of PQI Density Testing Method of Considering Texture Depth of Asphalt Pavement

Abstract

In recent years, nondestructive testing is applied more and more widely on the road detection, PQI as a kind of advanced testing equipment in asphalt pavement detection, it has been paid great attention by the road testing personnel. Based on the analysis of the densities which measured by PQI of different types of asphalt pavement, it sums up that the surface texture depth of asphalt pavement significantly affects the measuring accuracy of the density of PQI. In this paper, it suggests to use sand to fill the surface texture depth of asphalt pavement combining with PQI for pavement density measurement. Field testing shows that, compared with the bulk density of core sampling method, the density measured by PQI has obviously been affected by the surface texture depth of asphalt pavement. As the surface texture depth of the asphalt pavement is deeper, the error between the two methods is larger. Considering the influence of texture depth, the author improved the PQI detection method. The improved method shows that, compared with the bulk density of the core sampling, the coefficient of variation of the original testing method is 10.2%, and the new method is 3.8%. In the original testing method , it use the average value of the core sample densities as the compensation value of PQI measurement in the degree of compaction testing, and the maximum measurement error reached up to 2.2%. While, the improved testing method use the average value of the core sample densities as the compensation value of PQI measurement, the maximum measurement error reduces to 0.7%, the accuracy of the testing result is significantly improved.