Grading method and system suitable for recycled asphalt mixture, medium and equipment

Abstract

The invention provides a grading method and system suitable for recycled asphalt mixture, a medium and equipment. The method comprises the following steps: determining the particle sizes and respective passing rates of a minimum sieve mesh, a nominal maximum sieve mesh and a coarse and fine aggregate boundary point sieve mesh; obtaining grading curves of a coarse aggregate mixture and a fine aggregate mixture according to a Bloss grading curve model, obtaining grading curve model parameters by utilizing the determined sieve mesh diameters and passing rates of the sieve meshes, and obtaining apreliminary recycled asphalt mixture grading curve; and optimizing the passing rate of each sieve mesh according to the coarse aggregate mixture skeleton clearance rate in the coarse aggregate mixtureand the asphalt mixture to obtain an optimized recycled asphalt mixture grading curve which is used for grading design of the coarse and fine aggregate mixture. A continuous graded asphalt mixture with a suspension compact structure and a framework compact structure can be designed, the porosity of the recycled asphalt mixture can be effectively reduced, and the defects that the porosity of the recycled asphalt mixture is too large, and a grading curve deviates out of the upper limit and the lower limit due to grading refinement are overcome.

Description

technical field [0001] The present disclosure relates to the technical field of grading recycled asphalt mixtures, in particular to a grading method, system, medium and equipment suitable for recycled asphalt mixtures. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. [0003] The gradation (curve) of the aggregate mixture is formed by combining mineral materials of different sizes according to a certain mass ratio, and makes the aggregate mixture meet higher mechanical strength and greater compactness. The rationality of gradation composition design also plays a key role in the road performance of asphalt mixture. [0004] Some researchers proposed a gradation composition design method with aggregate mixture density as the characteristic parameter, that is, the power function parabolic curve construction method, also known as the n method, see fo...

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Problems solved by technology

However, the disadvantages of this operation are: first, the determination of the upper and lower limits of the gradation curve lacks a theoretical basis, and the critical values ​​are mostly determined according to actual engineering experience; The degree is reduced, the design process has a certain degree of blindness, and the rationality of the gradation design is greatly reduced; the third, and the most critical point, is that RAP (Reclaimed Asphalt Pavement, recycled asphalt mixture) waste materials are subjected to vehicles all year round before milling. The load rolling damage and the continuous mechanical hammering and crushing during the milling process make the particle size of the milled old mineral material generally finer than that of the new mixed mineral material, and accelerate the promotion of energy saving, emission reduction, and green environmental protection at home and abroad. Driven by the background, it is inevitable to greatly increase the blending ratio of RAP, which will cause the gradation composition of recycled asphalt mixture to be generally finer, which may exceed the upper and lower limits of the gradation value framed by the current gradation design method Fourthly, based on the existing method, the gradation design is carried out from the coarse aggregate mixture to the fine aggregate mixture, and the gradation curve is a whole single curve, but this cannot effectively reflect and utilize the coarse aggregate mixture and the fine aggregate mixture To implement more flexible and targeted grading scheme design based on the characteristics of fine aggregate mixtures

[0019] Finally, for the discontinuous gradation type, because of the basic absence of intermediate grade particle size mineral materials, it is easy to cause layering and segregation of coarse and fine aggregates, and the ease of construction is not as good as that of continuous grading. The segregated parts are not easy to compact, and there will be water damage such as potholes; in the segregated parts with more fine aggregates, there will be rutting, oil flooding and other diseases; and for recycled asphalt mixtures, due to the composition characteristics of multi-phase materials, the pavement The performance fluctuates greatly. If the mixing and compaction quality of the aggregate mixture cannot be effectively controlled, the probability of various diseases will increase sharply after the recycled asphalt pavement is in service.

Therefore, discontinuous gradation is not suitable for the gradation composition design of recycled asphalt mixture under the conditions of existing mix ratio technology and construction level.

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