Optimum design method for mineral aggregate gradation of hot recycled asphalt mixture

Abstract

The invention discloses an optimum design method for mineral aggregate gradation of a hot recycled asphalt mixture. The method comprises the steps of (1), determining engineering design gradation ranges; (2), testing the gradation of old mineral aggregates in new mineral aggregates and recycled asphalt pavement (RAP) materials; (3), testing the proportion of the old mineral aggregates with different specifications of fine particles, and the old mineral aggregates without coarse particles contained in the recycled asphalt pavement (RAP) materials, and carrying out discount calculation on the gradation of the old mineral aggregates according to test results; and (4), carrying out gradation optimum design on the hot recycled asphalt mixture according to the test and measurement results in the (1)-(3) and the engineering design gradation range. The gradation design method is high in practicability, the designed gradation of the recycled asphalt mixture is remarkably enabled to be more consistent with the engineering practice, the pavement performance of the hot recycled mixture is improved, and the service life of the hot recycled asphalt pavement is prolonged.

Description

technical field [0001] The invention belongs to the technical field of heat-regenerated asphalt pavement for urban roads, airport roads, highways, etc., and in particular relates to an optimal design method for mineral material gradation of heat-regenerated asphalt mixture. Background technique [0002] Most of my country's high-grade highways adopt asphalt pavement structure, and the design life is generally 12 to 15 years. Usually, it needs to be overhauled once after about 10 years. About 8,000-9,000 kilometers of highways need to be overhauled every year, producing nearly 50 million tons of waste asphalt mixture. On the one hand, the stacking of waste asphalt mixture not only occupies a large amount of land resources, but also causes serious environmental pollution; As a scarce resource, there is also the problem of over-exploitation. Asphalt pavement regeneration technology achieves the purpose of saving resources and protecting the ecological environment by reusing w...

AI Technical Summary

Problems solved by technology

During the mixing process, the fine-grained old ore covered by the old asphalt in the recycled asphalt pavement (RAP) cannot be completely separated from the coarse-grained old ore, and it cannot be evenly mixed with the new ore, making the hot recycled asphalt mixture The actual mineral material gradation is too thick, which does not match the design gradation

This result will lead to poor compactness of the molded hot recycled asphalt pavement, high water permeability coefficient, prone to early disease, and thus affect the service life

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