RAP掺量与新旧沥青融合程度对热再生混合料性能的影响

Effect of RAP Content and Mixing Degree of Aged and Virgin Asphalt on the Performance of Hot Recycled Asphalt Mixture

通过变化RAP掺量为20%~50%试验,研究常规未知新旧沥青融合状态与模拟新旧沥青100%融合状态下热再生混合料高温及低温性能、水稳定性、抗疲劳性能。结果表明:两种融合状态下,热再生混合料抗车辙性能均随RAP掺量增大而提高,低温抗裂性能和水稳定性均随RAP掺量增大而降低。新旧沥青融合程度和RAP掺量对热再生混合料的高温及低温性能、水稳定性、抗疲劳耐久性能有显著影响。与常规拌和工艺相比,新旧料100%融合工艺制备的热再生混合料其高温稳定性稍差,但具有更好的低温抗裂性能、水稳定性和抗疲劳耐久性能,配合比设计时应考虑新旧沥青融合程度对高RAP掺量热再生混合料路用性能与抗疲劳耐久性能的影响。

This paper mainly studies the properties,water stability and fatigue resistance of the hot recycled mixtures under the conventional unknown aged and virgin asphalt blending state and the simulated virgin and aged asphalt 100%mixing state.According to the results,the hot recycled mixture's rutting resistance was directly proportional to the RAP content,while its low temperature cracking resistance and water stability was inversely proportional to the RAP content.The mixing degree of aged and virgin asphalt and RAP content significantly affects the hot recycled mixture's high and low-temperature properties,water stability and fatigue durability.In comparison with the conventional mixing process,hot recycled mixture prepared by 100%mixed aged and virgin materials is of slightly poor high-temperature stability,but better low-temperature cracking resistance,water stability and fatigue durability.The effect of the mixing degree of aged and virgin asphalt on pavement performance and fatigue durability of hot recycled mixture with high RAP content should be considered in the design of mix ratio.