乳化沥青冷再生混合料低温性能研究

Research on the Low Temperature Performance of Emulsified Asphalt Cold Recycled Mixtures

随着乳化沥青冷再生混合料逐渐在高等级公路较高层位的应用,其低温抗裂性能需要引起更多的关注。通过半圆弯曲(Semi Circle Bending,SCB)试验,采用断裂能指标评价乳化沥青冷再生混合料的低温性能,提出不小于1 000J/m2的评价标准。同时与低温弯曲试验进行对比分析,结果表现出相同的变化规律,即不添加水泥的乳化沥青冷再生混合料其低温性能相对较差,随着水泥用量的增加,冷再生混合料低温性能逐渐提高,但随着水泥用量的继续增加,冷再生混合料表现出一定的脆性,导致混合料的低温性能降低,因此,建议乳化沥青冷再生混合料设计时应严格控制水泥用量,并建议水泥用量不超过1.5%为宜。

As the emulsified asphalt cold recycled mixtures is used in the surface layer of high-grade roads,the low temperature crack resistance needs more attention.In this paper,the semi circle bending test is used to evaluate the low temperature performance of emulsified asphalt cold recycled mixtures.The breaking energy is taken as the evaluation index,and the corresponding strength criterion of not less than1000J/m2 is presented.Low temperature tensile tests are also performed for comparison and analysis.The same result that the low temperature performance is gradually improved with the increase of cement content is obtained.However,when the cement is beyond some content,the mixture shows some brittleness,and result in the decrease of low temperature performance.Therefore it is suggested that the amount of cement should be strictly controlled during emulsified asphalt cold recycled mixture design,and the dosage is recommended less than 1.5%.