级配对乳化沥青冷再生混合料路用性能影响

Influence of gradation on pavement performance of emulsified asphalt cold regenerated mixture

为了优化乳化沥青冷再生混合料级配,采用垂直振动试验方法研究矿粉、机制砂和9.5~19mm粗集料对冷再生混合料路用性能的影响.研究表明:矿粉对其水稳定性、低温抗裂性没有明显影响,矿粉掺量为3%时,与不掺矿粉相比冷再生混合料的动稳定度可提高41%;机制砂掺量为20%时,与不掺新集料相比,冻融劈裂强度比、动稳定度、弯拉强度可分别提高10%、54%、13%;9.5~19mm粗集料对低温抗裂性能没有明显影响,与不掺新集料相比,9.5~19 mm粗集料掺量为10%~30%时,冻融劈裂强度比、动稳定度可分别提高7%~11%、151%~208%.建议冷再生混合料中9.5~19mm粗集料掺量10%~30%、机制砂掺量20%、矿粉掺量3%为宜.

In order to optimize the gradation of the emulsified asphalt cold regenerated mixture,the effect of mineral powder,mechanism sand and 9.5-19 mm coarse aggregate on the pavement performance of the cold regenerated mixture was studied by means of vertical vibration test.The results show that the effect of mineral powder on water stability and low temperature crack resistance is not significant.The dynamic stability of the cold regenerated mixture with 3%of mineral powder increases by 41%compared with that of the mixture with no added mineral powder.When the content of the mechanism sand is 20%,compared with the mixture with no added aggregate,the ratio of freeze-thaw cleavage strength,dynamic stability and bending tensile strength can be increased by 10%,54%and 13%respectively.The effect of 9.5-19 mm coarse aggregate on low temperature crack resistance is not significant.When the content of 9.5-19 mm coarse aggregate is between 10%and 30%,compared with the mixture with no added aggregate,the ratio of freeze-thaw cleavage strength and dynamic stability can be increased by 7%-11%and 151%-208%respectively.It is suggested that the best mix proportion of cold regenerated mixture is 10%-30%of 9.5-19 mm coarse aggregate,20%of mechanism sand and 3%of mineral powder.