Preparation method of plant-mixed hot recycled asphalt mixture

Abstract

The invention discloses a preparation method of a plant-mixed hot recycled asphalt mixture. The preparation method comprises the following steps: (1) after heating new aggregates, adding the new aggregates into a mixing cylinder; (2) after heating part of new asphalt, adding the heated new asphalt into the mixing cylinder for the product obtained in the step (1) for mixing; (3) after heating RAP (recycled asphalt pavement) materials, adding the RAP materials into the mixing cylinder for the product obtained in the step (2); (4) adding the rest of new asphalt into the mixing cylinder with the product obtained in the step (3) for mixing; (5) adding mineral powder into the mixing cylinder for the product obtained in the step (4) for mixing; and (6) taking the mixture obtained in the step (5) out of the cylinder and carrying out forming. The method disclosed by the invention has the advantages of easy implementation, high recycling efficiency of old materials, small use quantity of the new asphalt, effective prevention from generating grizzled materials in the recycled mixture, higher uniformity of the recycled mixture and better performance.

Description

Technical field [0001] The invention belongs to the technical field of road engineering and relates to a method for preparing a plant-mixed hot regenerated asphalt mixture. Background technique [0002] The production process of plant-mixed hot recycled asphalt mixture is to transport waste asphalt pavement materials (RAP) to asphalt mixing plants (sites, stations), crush and screen them, and then mix them with new aggregates, new asphalt, and asphalt in a certain proportion. A hot-mix regenerated mixture made of regenerant (if necessary). Its main function is to repair asphalt pavement surface layer diseases, restore or even improve the road performance of asphalt pavement mixture, and realize the recycling of old pavement asphalt layer materials in the form of hot mix asphalt mixture. It has the advantages of easy control of the regeneration process, better performance of the regenerated asphalt mixture, and wide application range. However, in the conventional mixing process,...

AI Technical Summary

Problems solved by technology

This mixing process does not take into account the difference between the new aggregate and the old material (with asphalt coating), resulting in the difference between the new aggregate and the old material in the recycled mixture after mixing. The uniformity is poor, and the new aggregate with large particle size is often not fully coated with asphalt after mixing, showing the phenomenon of graying material

In order to control the occurrence of graying material, sometimes the addition of new asphalt has to be increased, which not only increases the difference between the production mix ratio of the recycled mixture and the design mix ratio, but also affects the performance of the recycled mixture; at the same time, it causes a waste of asphalt resources, Reduced economic advantage of recycled mixes

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