Asphalt mixture mixing proportion design method based on inert solid fractal distribution characteristic

Abstract

The invention relates to a method of designing a mixed ratio for a bitumen mixture based on fractal and distributional features of ore materials. The method comprises the following steps: (1) mathematical models for particle diameter distribution and mass distribution of the ore materials are set up respectively; (2) the type and the grading limit of the bitumen mixture are determined; (3) raw materials are selected and checked; (4) graduations of two arbitrary groups of the ore materials are determined and corresponding fractal dimension values(D) are worked out; (5) the use level of the bitumen is worked out; (6) the bitumen mixture is prepared by stirring; (7) a Marshall test sample is made, the relative density of the bulk volume of the test sample is determined, the theoretical maximum relative density is determined, and the volume index is worked out; (8) relationship curves between the fractal dimension values(D) and the volume indexes are drawn; (9) the graduation of the ore materials and the optimum use level of the bitumen are determined; (10) the road performance of the bitumen mixture is tested; and (11) the construction mixed ratio of the bitumen mixture is determined. The invention utilizes the fractal theory to set up the mathematical models, and in the process of designing the mixed ratio of the bitumen mixture, the optimum bitumen use level and the optimum graduation of the ore materials meeting and regulating all design rules of the bitumen mixture can be quickly determined.

Description

technical field [0001] The invention relates to the mix ratio of asphalt mixture for the surface layer of asphalt pavement, in particular to a design method for the mix ratio of asphalt mixture based on the fractal distribution characteristics of mineral materials. Background technique [0002] Hot mix asphalt mixture is a composite material composed of mineral aggregates, asphalt, and mineral powder, and is one of the most important building materials for asphalt pavement. High-quality asphalt mixture has good road performance such as high-temperature stability, low-temperature crack resistance, and fatigue resistance. It can resist possible damage caused by the natural environment and traffic loads, delay the time of damage to the asphalt pavement, and save maintenance costs. [0003] The mix ratio design of hot mix asphalt mixture is usually completed in three stages: target mix ratio design, production mix ratio and production mix ratio verification. The target mix ratio...

AI Technical Summary

Problems solved by technology

Therefore, the workload of determining the optimal asphalt dosage is relatively large, and after several weighted averages, the relationship between the asphalt dosage and the mineral material gradation cannot be considered, resulting in the "best asphalt dosage" not necessarily being the best fact

[0011] Throughout the domestic and foreign Marshall asphalt mixture design methods are mainly based on experience and a large number of experiments, there has not been a traditional method to break through the maximum density curve theory to determine the mineral material gradation and a large number of experiments to determine the mixture ratio in theory and practice. As a result, it only takes about 7 days for experienced road engineers to complete the design of an asphalt mixture, while inexperienced road engineers need 2 to 3 months or even half a year to complete the design of an asphalt mixture. current situation

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