【摘要】 为考察半刚性基层沥青路面在超重高频动载及环境温度交互作用下的力学响应状况,采用MLS66在高温及常温条件下进行半轴超载50%的足尺加速加载试验。结合加载次数、温度、模量等参数,分析了可控荷载条件下路面结构层底部三向瞬时及累积应变响应的空间分布及时程变化,并对实测值与计算值进行了对比分析。结果表明:面层底部瞬时应变实测值大于计算值,基层中两者较吻合;纵向瞬时应变比为1/5~1/2,且温度越高,应变比越小;高温下瞬时应变幅值为常温下的2~6倍;面层纵向应变温度系数约为横向的2倍,基层(底基层)的三向应变温度系数大致相同;瞬时应变幅值和应变温度系数与路面深度分别呈幂指数、负线性关系;加载次数与累积应变、地震波模量呈双对数线性关系,可用于沥青面层疲劳预估。更多还原

【Abstract】 In order to investigate the mechanical response of semi-rigid base asphalt pavement under overweight and mobile high-frequency load along with temperature impact,a full-scale accelerated pavement testing(APT)with mobile load simulator 66(MLS66)was conducted.The test simulated a half-axle load,50% higher than the standard,at high and normal air temperature.Considering the parameters of loading applications,temperature,modulus and so on,analysis of the spatial distribution and time-history change of three-dimensional instantaneous and cumulative strains at the bottom of each layer was made.Moreover,calculated and measured strains were compared.The results show that the instantaneous strains measured at each surface layer bottom are greater than the calculated values,while generally good agreement is found between the calculated and measured strains of base or subbase.The longitudinal instantaneous strain ratios are 1/5-1/2,and the higher the temperature,the smaller the strain ratio.The instantaneous strain amplitudes under high temperature are 2-6times of those under ambient temperature.The longitudinal strain-temperature coefficient is twice of transverse one at bottomof asphalt layer,while the temperature coefficients of three-dimensional strains in base or subbase are equal roughly.The amplitude of instantaneous strain and strain-temperature coefficient decrease with the depth following power and linear function respectively.There is a double logarithmic relationship among the loading applications,cumulative strain and seismic modulus,which can be used to estimate the pavement fatigue.更多还原