不同制备工艺对乳化沥青冷再生混合料路用性能的影响

Effect of In-Service Performance of Emulsified Asphalt Cold Recycled Mixture Produced by Different Production Processes

摘要: 在传统乳化沥青冷再生混合料制备工艺中存在集料不易于被乳化沥青均匀包裹、两者之间粘附性不足的问题。为解决上述问题，将预拌及振动搅拌工序应用于乳化沥青冷再生混合料的制备过程中，进而改善其路用性能。本文分别比较了传统拌和、预拌、振动拌和以及振动预拌这四种制备工艺下乳化沥青冷再生混合料的外观特征、体积特性。同时，对混合料冻融循环前后的路用性能进行了测试。实验结果表明，预拌、振动拌和以及振动预拌均能够使乳化沥青充分均匀地裹覆于集料表面，防止了花白料的产生。振动预拌工艺会增加集料小于13.2 mm筛孔的质量通过率，进而使混合料的空隙率变小。相比于传统制备工艺，振动预拌工艺的冷再生沥青混合料空隙率下降了0.418%，低温劈裂抗拉强度提高了17.3%，高温性能及疲劳寿命具有一定的提升。而且，根据乳化沥青冷再生混合料经历5次冻融循环后的性能可得知，振动预拌工艺可以提升再生混合料的冻融损伤耐久性。

Abstract: In the traditional production process of Emulsified Asphalt Cold Recycled Mixture (EACRM), the aggregate is difficult to be evenly coated by emulsified asphalt, and the adhesion between them is seriously insufficient. In order to solve the above problems, vibration mixing and premixing processes were applied in the EACRM production process to improve its in-service performance. In this paper, the appearance characteristic and volume characteristic of EACRM prepared by traditional mixing, premixing, vibratory mixing and vibration premixing processes were evaluated. Meanwhile, the in-service performance of EACRM before and after freeze-thaw cycles was tested. The results indicate that the production processes of premixing, vibratory mixing and vibration premixing can make the emulsified asphalt evenly coat on the aggregate and prevent the appearance of uncoated aggregates. The vibration premixing process can increase the passing quality percentage of aggregate with screen holes of less than 13.2 mm, thereby decreasing the air void of EACRM. Compared with the traditional mixing process, the air void of EACRM produced by the vibration premixing process decreases by 0.418%, and the low-temperature indirect tensile strength increases by 17.3%, and the high-temperature performance and fatigue life improved to some extent. Furthermore, it can be found from the in-service performance result of EACRM after five freezing-thawing cycles that the vibration premixing process can improve the resistance to freeze-thaw damage of EACRM.