The Research Of Load-bearing Skeleton Aggregate Gradation Design Method

Due to the sharp increase in traffic, making the pavement rutting phenomenon occurs more frequently, so the aggregate gradation design method proposed new requirements.Coarse aggregate in asphalt mixture plays an important role, it is not only the main bearing,but still the largest contributor to the mixture of high-temperature stability. The current methods are inadequate grading design reflects its importance, so the design method based on aggregate grading bearing performance has become imperative. Meanwhile, the asphalt mixture design method should also be improved and perfected accordingly proposes a mix design method based on mechanical properties of hybrid materials are also available without delay.This paper will be based on the existing research by CBR instrument of coarse aggregate gradation conduct penetration testing, through comparative analysis of the test, obtained the penetration test various test conditions: coarse aggregate forming method using dry tamping method, the penetration rate using 50 mm / min, pressure head diameter using the penetration depth and the number of 50 mm and 16.67 mm parallel test for 3 times. Meanwhile, the paper will feature six different groups of coarse aggregate penetration tests conducted to measure various aggregate gradation penetration load curve analysis of the penetration, penetration characteristics of gradation between using Bailey Act III evaluation parameters and exponent of six graded evaluated; get graded characteristics and power regression correlations between parameters.This paper will consider the mix while the mechanical properties of asphalt mixture design method research proposed will replace Marshall stability IDT strength to determine the optimum asphalt content of asphalt mixture method. Through the four types of material were mixed with the ratio test and the indirect tensile test(split test), was found by analyzing the test results to determine the optimum amount of asphalt mix approach based IDT strength advantage, but also will integrate the mechanical indicators road asphalt mixture design method were.Article concludes with a fluctuation range to determine the construction method of grading, construction grading fluctuation range of the method for determining both to establish contact with the mixture performance, but also to distinguish between the different requirements of different types of mixes.Overview of text, the first of aggregate penetration methods were studied in detail,suggestions penetration method values; then use the method to determine the penetration of six different groups with coarse aggregate penetration tests carried out to measure the Its penetration load; proposed and validated to determine optimum asphalt content IDT strength based approach, and finally proposed construction grading fluctuation range of research and calculation method based on performance.