沥青路面蠕变响应现场预估方法与试验

发布时间：2018-03-26 16:44

本文选题：道路工程　切入点：蠕变　出处：《中国公路学报》2017年09期

【摘要】：为了揭示在役沥青路面结构的黏弹特性,给基于黏弹性本构的沥青路面设计提供参考,针对现有沥青路面应变测试仍然基于弹性假设的现状,依据三维线黏弹本构理论,通过现场埋设应变和温度传感器,开展不同温度与轴载作用下的沥青路面静载蠕变试验。基于实测应变变化规律对现有表征沥青混合料黏弹性本构模型的适用性进行了判别,并分析温度、偏应力等外部影响因素对沥青层黏弹性参数的影响规律,由此建立沥青路面应变随外部因素变化的预估模型。结果表明:实测蠕变历时曲线呈现的黏弹特性很好地符合Burgers模型,拟合判定系数超过0.98;Burgers模型的4个参数(G_1,G_2,η_1及η_2)均随温度的提高而减小,随偏应力的增加而增大,与偏应力、温度分别呈良好的线性和指数函数关系,拟合相关系数均大于0.84,其中黏性参数η_1和η_2受温度和偏应力的影响显著;按应变预估模型计算得到的应变与同等工况下的实测应变历时曲线规律吻合,应变值的相对误差在10%以内,表明建立的基于三维黏弹本构关系的沥青面层应变预估方法合理、可行。
[Abstract]:In order to reveal the viscoelastic properties of existing asphalt pavement structure and provide a reference for the design of asphalt pavement based on viscoelastic constitutive law, aiming at the present situation that the existing asphalt pavement strain test is still based on elastic assumption, the three-dimensional linear viscoelastic constitutive theory is used. The static creep tests of asphalt pavement under different temperatures and axial loads were carried out through the installation of strain and temperature sensors in the field. The applicability of the existing viscoelastic constitutive models of asphalt mixtures was judged based on the measured strain variation law. The influence of external factors, such as temperature and deflection stress, on the viscoelastic parameters of asphalt layer is analyzed. A prediction model of asphalt pavement strain varying with external factors is established. The results show that the viscoelastic properties of the measured creep curve are in good agreement with the Burgers model. The four parameters of the fitting judgement coefficient more than 0.98 / Burgers model (G _ 1 / G _ 2, 畏 _ S _ 1 and 畏 _ 2) all decreased with the increase of temperature, and increased with the increase of deviant stress, and showed a good linear and exponential relationship with the deviation stress and temperature, respectively. The fitting correlation coefficients are all greater than 0.84, in which the viscosity parameters 畏 _ 1 and 畏 _ 2 are significantly affected by temperature and deflection stress, and the strain calculated by the strain prediction model is consistent with the measured strain duration curve under the same working conditions. The relative error of strain value is less than 10%, which indicates that the method of strain prediction based on three-dimensional viscoelastic constitutive relation is reasonable and feasible.
【作者单位】：长沙理工大学交通运输工程学院;长沙理工大学公路养护技术国家工程实验室;
【基金】：国家自然科学基金项目(51578081,51608058) 交通运输部建设科技项目(2015318825120) 重庆市教委科学技术研究项目(KJ1705133)
【分类号】：U416.217

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