摘要
为更准确评价道路交叉口沥青路面材料的高温稳定性,对标准动态蠕变试验的加载模式进行改进。在考虑交叉口特殊交通荷载环境的基础上,提出常速行驶、减速行驶、低速行驶和停止4种驾驶行为的加载方式。通过改进型动态蠕变试验,对4种不同沥青混合料的高温蠕变指标(流变次数Fn和流变速率Cr)进行分析。结果表明:从常速加载模式到停止模式,4种沥青混合料的Fn均下降且Cr均上升,说明在低速行驶或停止加载模式下,沥青混合料更容易发生蠕变损伤;在不同加载模式下,高强改性沥青混合料均表现出最高的Fn和最低的Cr,说明高强改性沥青在复杂交通荷载环境下的高温稳定性最好;添加纤维对提升沥青混合料的高温稳定性具有积极作用;不同加载模式对沥青混合料高温稳定性的区分度存在差别。考虑道路交叉口的特殊性,可采用条件更为苛刻的低速行驶或者停止加载模式进行材料室内设计。
To better evaluate the high-temperature performance of the asphalt pavement at intersection area,the standard dynamic creep test was modified.Considering the complex traffic and environmental conditions at pavement intersection,four different loading conditions describing four driving behaviors of normal speed,deceleration,low speed and stopping were incorporated into the dynamic creep test.The creep indexes including flow number(Fn)and creep strain rate(Cr)of four different asphalt mixtures were investigated through the modified dynamic creep test.The testing results show that the Fn of all asphalt mixtures decreased and Cr of all asphalt mixtures increased when the loading mode switches from the normal speed to stopping,which means the asphalt mixture is prone to the rutting distress under low speed or stopping loading condition.The high-strength modified asphalt mixture presented the highest Fn and lowest Cr at different loading conditions,which indicates that the high-strength modified asphalt mixture has the best rutting resistance performance among the four asphalt mixtures under the complex traffic environment.The addition of the fiber could improve the high-temperature performance of the asphalt mixture to some extent.Different loading modes could differentiate the high-temperature performance of the asphalt mixture differently.Taking the complex service condition of the pavement intersection into account,it is recommend to use the harsher loading modes such as the low speed and stopping for the laboratory mixture design.
作者
汪义
王海涛
梅鸽福
王晨炜
WANG Yi;WANG Haitao;MEI Gefu;WANG Chenwei(China Nuclear Industry Zhongyuan Construction Co.,Ltd.,Beijing 100142,China)
出处
《施工技术》
CAS
2021年第7期132-136,共5页
Construction Technology
基金
淮安市科技指导性项目(2020ZD001103)
关键词
道路
交叉口
沥青混合料
高温稳定性
动态蠕变试验
加载方式
流变次数
pavement
intersection
asphalt mixture
rutting resistance
dynamic creep test
loading condition
flow number
