High-addition-amount plant-mixed warm regenerated asphalt mixture and preparation method thereof

Abstract

The invention discloses a high-addition-amount plant-mixed warm regenerated asphalt mixture and a preparation method thereof. The high-addition-amount plant-mixed warm regenerated asphalt mixture includes the following components, by mass, 40-80% of waste asphalt mixture, 16-47% of aggregate, 0-1% of mineral powder, 1-3.5% of asphalt, a regenerating agent accounting for 2-8% of the quantity of the waste asphalt mixture and a warm-mixing agent accounting for 2-6% of the total quantity of the asphalt. The mixing temperature of the waste asphalt mixture and the aggregate can be reduced by 20-30 DEG C. The asphalt mixture can delay aging degree of waste asphalt in the waste asphalt mixture and can be fully compacted in a certain temperature range, which is beneficial to use quantity of an asphalt pavement in later period and also reduces energy consumption and harmful gas emission during the mixing and construction process. The various pavement performance of the high-addition-amount plant-mixed warm regenerated asphalt mixture is similar as that of a common asphalt mixture. The asphalt mixture is improved in high-temperature stability by 20-40%, is improved in fatigue performance by 10-15% than the regenerated asphalt mixture without addition of the warm-mixing agent, and ensures the pavement performance.

Description

technical field [0001] The invention relates to an asphalt mixture, in particular to a high-volume factory-mixed temperature recycled asphalt mixture and a preparation method thereof. Background technique [0002] High-volume plant-mix heat regeneration means that the amount of old asphalt accounts for more than 25% of the total asphalt. At present, the plant-mix heat regeneration technology with old asphalt content less than 25% is relatively mature, and research shows that it has the same performance as fresh mix The performance of asphalt mixture is even better in some aspects; however, for the recycled mixture with the content of waste asphalt mixture (RAP) greater than 25%, the evaluation and research on its performance have not yet come to a definite conclusion. accepted conclusion. Based on this, some states in the United States stipulate that the amount of RAP in the recycled mixture used as the upper layer is not allowed to exceed 30%. It can be seen that due to c...

AI Technical Summary

Problems solved by technology

It can be seen that due to concerns about the low-temperature cracking performance and fatigue performance of recycled mixtures with high RAP content, the content of RAP is strictly limited when applying recycled mixtures to high-grade roads or upper-middle asphalt pavements, which is extremely The earth restricts the development and application of high RAP content plant mixing heat regeneration technology

[0003] At the same time, the following problems also exist in the actual implementation of high-volume plant-mix hot regeneration: 1. The asphalt of the recycled mixture is seriously aged

The construction temperature of factory-mixed hot recycled mixture is generally 5-15°C higher than that of conventional hot-mixed mixture, and the proportion of old materials added is increased. In order to ensure the construction temperature of the mixture, the new aggregate is required to have a higher heating temperature, resulting in The short-term aging of thermal recycled mixture is serious during the construction process; 2. The energy consumption of mixture production is high

Due to the further increase in the dosage of RAP materials, the temperature in the production process will increase and the mixing time will be prolonged, which will reduce the production efficiency of the mixing plant to a certain extent and increase the production cost of the mixture; 3. The emission of harmful gases will increase significantly

The increase in temperature and the extension of mixing time in the production process will greatly increase the emission of blue smoke and harmful gases

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