Preparation method of separated plant-mixed warm-hot regenerated asphalt mixed material

Abstract

The invention relates to an asphalt material for pavement engineering and in particular to a preparation method of a separated plant-mixed warm-hot regenerated asphalt mixed material. The preparation method comprises the following steps: (1) detecting the asphalt content of a recovered asphalt pavement material, ageing the asphalt performance and mineral aggregate gradation; (2) determining the content of the recovered asphalt pavement material, a novel aggregate, limestone mineral powder, novel asphalt and a regenerator; (3) adding the mixture into a mixing pot for prestirring; (4) adding the regenerator; (5) discharging the obtained product out of a pot and developing at 40-150 DEG C; (6) adding the heated novel aggregate into the stirring pot, adding the developed product in the step (5) and stirring; and (7) adding the novel asphalt and limestone mineral powder into the product obtained in the step (6) and stirring, and then discharging and forming. The asphalt material provided by the invention is simple in process, good in regenerating effect, high in utilization ratio of the regenerator, relatively low in cost and good in comprehensive pavement performance of the product.

Description

technical field [0001] The invention relates to an asphalt material used in road surface engineering, in particular to a preparation method of a separated plant-mixed warm-heated regenerated asphalt mixture. Background technique [0002] Plant-mix heat recycling technology is the most commonly used asphalt pavement regeneration method in the world today. It is suitable for the recycling of old asphalt concrete pavement under various conditions. It not only saves a lot of raw materials such as asphalt and gravel, but also saves engineering investment and avoids new resources. consume. At the same time, it is beneficial to deal with waste and protect the environment, so it has significant economic benefits, social and environmental benefits. [0003] In the traditional plant-mixed heat regeneration process, the old asphalt mixture (referred to as old material) and new aggregate are generally heated separately, and then the old material and new aggregate are mixed in a mixing ...

AI Technical Summary

Problems solved by technology

However, the traditional process does not take into account the interaction between the new asphalt and the aged asphalt in the old material, and the close combination needs to be fully completed under specific temperature and time conditions. On the one hand, the new aggregate and the old material in the recycled mixture after mixing The degree of asphalt coating is different. The asphalt film of new aggregates is often thin, while the asphalt film of old materials is thick. The uniformity of the mixture is poor. Often, new aggregates with large particle sizes are not fully coated with asphalt after mixing, and appear On the other hand, the new asphalt and the aged asphalt in the old material are not completely fused and evenly attached to the new and old aggregates, resulting in that the road performance of the aged asphalt cannot be fully improved and regenerated. The two kinds of asphalt are separated in the mixture system Give full play to the original characteristics and cannot form a unified whole

As a result, the comprehensive road performance of the recycled asphalt mixture is seriously affected, especially the water stability, low temperature crack resistance and fatigue life are all greatly reduced compared with the asphalt mixture using all new materials.

In addition, when the regenerant is directly added to the mixture of new aggregates and old materials, many of them are absorbed and absorbed by the new aggregates, and cannot regenerate the aged asphalt, resulting in a decrease in the effective utilization of the regenerant and an increase in Production cost of recycled asphalt mixture

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