CAJ | 학술논문

在应变控制模式下对3种不同级配的沥青混合料进行了四点弯曲小梁疲劳试验，对采用耗散能相对变化率的突变点（判据1）和劲度模量下降至初始劲度模量的50％（判据2）两种失效判据得到的沥青混合料疲劳寿命进行了对比，并针对两种失效判据构建了疲劳寿命预测模型。结果表明：混合料的初始劲度模量随应变水平及公称最大粒径的增大而减小；以判据1为失效判据时，同一沥青混合料在不同应变水平下破坏时的劲度模量基本相同，不同沥青混合料破坏时的劲度模量随公称最大粒径的增大而减小，获得的疲劳寿命比以判据2为失效判据获得的疲劳寿命长；沥青混合料的疲劳寿命随应变水平及公称最大粒径的增大而大幅减小；判据1对应的疲劳寿命预测模型准确性更高。
재응변공제모식하대3충불동급배적력청혼합료진행료사점만곡소량피로시험，대채용모산능상대변화솔적돌변점（판거1）화경도모량하강지초시경도모량적50％（판거2）량충실효판거득도적력청혼합료피로수명진행료대비，병침대량충실효판거구건료피로수명예측모형。결과표명：혼합료적초시경도모량수응변수평급공칭최대립경적증대이감소；이판거1위실효판거시，동일력청혼합료재불동응변수평하파배시적경도모량기본상동，불동력청혼합료파배시적경도모량수공칭최대립경적증대이감소，획득적피로수명비이판거2위실효판거획득적피로수명장；력청혼합료적피로수명수응변수평급공칭최대립경적증대이대폭감소；판거1대응적피로수명예측모형준학성경고。
Four-point bending beam fatigue tests of three kinds of graded asphalt mixtures were carried out in the strain control mode,and two criteria for fatigue life prediction,namely the catastrophe point of the relative change rate of dissipated energy (Criterion 1 )and the stiffness modulus decreasing to 50%of the initial stiffness modulus (Criterion 2),were compared.Then,two fatigue life prediction models respectively corresponding to the two crite-ria were constructed.The results show that (1 )the initial stiffness modulus of the mixture decreases with the in-crease of strain level and nominal maximum particle size;(2)when Criterion 1 is used as the failure criterion,the same mixture mostly destroys with the same stiffness modulus at different strain levels,the destruction stiffness modulus of different mixtures decreases with increase of nominal maximum particle size,and the predicted fatigue life is longer than that predicted by Criterion 2;(3 )the fatigue life of asphalt mixture significantly decreases with the increase of the strain level and the nominal maximum particle size;and (4 )the fatigue life prediction model corresponding to Criterion 1 is of higher accuracy.