Nonlinear Fatigue Damage Model of Asphalt Mixture Based on Dynamic Modulus and Residual Strength Decay
Nonlinear Fatigue Damage Model of Asphalt Mixture Based on Dynamic Modulus and Residual Strength Decay
复制标题
基于动态模量和残余强度衰减的沥青混合料非线性疲劳损伤模型
DOI：
10.3390/ma12142236
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发表时间：
2019-07-02
期刊：
影响因子：
3.4
通讯作者：
Lv, Songtao
中科院分区：
文献类型：
--
作者：
Liu, Hongfu;Yang, Xinyu;Lv, Songtao
为了更合理地描述沥青混合料的疲劳损伤状态，在1.00MPa、0.50MPa和0.25MPa应力水平下进行了疲劳及残余强度的直接拉伸试验，每组应力水平设置5个平行试验。AC - 13C沥青混合料小梁试件（25cm×5cm×5cm）采用苯乙烯 - 丁二烯 - 苯乙烯（SBS）改性沥青、玄武岩集料和石灰石矿粉制作而成，最佳油石比为5.2%。分别将动态模量衰减和残余强度衰减定义为损伤变量，以评估沥青混合料的疲劳损伤过程。基于试验结果，揭示了不同应力状态下疲劳试验过程中动态模量和残余强度的衰减规律，并根据相应的衰减规律得到了疲劳损伤模型及参数。然后，基于残余强度和动态模量取决于相同损伤状态这一假设，给出了两种损伤定义之间的关系，并建立了残余强度 - 动态模量耦合模型。结果表明，残余强度 - 动态模量耦合模型能更好地描述沥青混合料的疲劳损伤演化规律，且该耦合模型的参数可通过较少的残余强度试验获得。基于两类损伤变量之间的关系，提出了一种计算与残余强度和动态模量相关的损伤变量的修正公式。
In order to describe the fatigue damage state of asphalt mixture more reasonably, direct tensile tests of the fatigue and the residual strength under stress levels of 1.00 MPa, 0.50 MPa and 0.25 MPa with five parallel tests were carried out. The trabecular specimens of AC-13C asphalt mixture (25 cm × 5 cm × 5 cm) were manufactured with Styrene-Butadiene-Styrene (SBS) modified asphalt, aggregate basalt and limestone mineral filler. The optimum asphalt-aggregate ratio was 5.2%. The dynamic modulus decay and the residual strength decay were termed as the damage variables to evaluate the fatigue damage process of asphalt mixtures, respectively. Based on the test results, the decay patterns of the dynamic modulus and the residual strength during fatigue tests under different stress states were revealed, and the model and the parameters of fatigue damage according to the corresponding decay patterns were obtained. Then, based on the assumption that the residual strength and dynamic modulus depend on the same damage state, the relationship between the two damage definitions was given, and the residual strength-dynamic modulus coupled model was established. The results showed that the residual strength-dynamic modulus coupled model could better describe the fatigue damage evolution law of asphalt mixture, and the parameter of this coupled model could be obtained by less residual strength tests. A modified formula for calculating the damage variables associated with residual strength and dynamic modulus was proposed based on the relationship between two kinds of damage variables.