Treatment method for realizing high-mixing-amount and high-quality recycling of RAP

Abstract

The invention discloses a treatment method for realizing high-mixing-amount and high-quality recycling of RAP. The treatment method comprises the following steps: S1, setting a command and control standard of RAP in a recycled asphalt utilization mixture; S2, milling and recycling the old pavement, and primarily screening the milled and recycled RAP in a unified mode; S3, performing crushing and shaping on the RAP subjected to primary screening; S4, grading and screening the crushed and shaped RAP, and grading and selecting the RAP meeting the command and control standard in the step S1; and S5, performing hot mix plant recycling on the selected RAP. According to the treatment method for realizing large-dosage and high-quality recycling of the RAP, a pretreatment process of the RAP is optimized, the RAP is primarily screened firstly, then the RAP on the screen is crushed and then screened in grades until the treated RAP meets the large-dosage controllable use requirement, the standardized treatment efficiency and quality are remarkably improved, and the RAP variability is reduced.

Description

technical field [0001] The invention relates to the technical field of road engineering materials, in particular to a processing method for realizing high-volume, high-quality recycling of RAP. Background technique [0002] In recent years, domestic expressways have developed rapidly. The total mileage of national expressways has exceeded 160,000 kilometers, and the mileage of expressways in Fujian Province has exceeded 6,000 kilometers. There is a huge amount of old road asphalt mixture. If it is not recycled, the stacking of a large amount of old road asphalt mixture will cause huge pressure on land occupation and the environment. Under the current technological level, in the factory-mixed recycled asphalt mixture whose performance meets the requirements, the utilization rate of RAP is generally only 20-40%, and the economy of RAP recycling is limited, resulting in low enthusiasm for technology promotion and application. In August 2019, the new version of "Technical Speci...

AI Technical Summary

Problems solved by technology

Under the current technological level, in the plant-mixed recycled asphalt mixture whose performance meets the requirements, the utilization rate of RAP is generally only 20-40%, and the economical efficiency of RAP recycling is limited, resulting in low enthusiasm for technology promotion and application

In August 2019, the new version of "Technical Specifications for Recycling of Highway Asphalt Pavement" (JTG / T 5521-2019) was promulgated, canceling the recommended value of no more than 30% of the mixed heat regeneration of asphalt pavement plants, and reducing the penetration of old asphalt to not less than 20 (0.01mm) technical index requirements, but there is still no practical and feasible process method for the real realization of large dosage (greater than 40%) and high-quality utilization of old road asphalt mixture, and related technical achievements are still being explored. Recycling with high value and high performance can not only reduce waste and protect the environment, but also has considerable economic benefits, which is the only way for sustainable development in the field of asphalt pavement maintenance in the future

[0003] At present, with regard to the utilization of recycled asphalt mixture, most scholars believe that by strictly controlling the RAP milling process and strengthening the fine management of RAP, the variability in the use of RAP can be effectively reduced, so as to obtain a recycled asphalt mixture with stable performance. Theoretically, this method can achieve the expected goal, but in the actual process, strictly controlling the RAP milling process and strengthening the RAP fine management will increase the workload of the construction party, and the requirement for the mixing station area is relatively high, which is not easy to achieve Large-scale promotion and use of RAP

Images