基于疲劳累积损伤的高模量沥青路面使用寿命预估
Life prediction of high modulus asphalt pavement based on？？fatigue cumulative damage

为了精确预估高模量沥青路面的使用寿命，以疲劳累积损伤理论为基础，提出考虑沥青路面结构温度分布、轴载分布以及沥青混合料疲劳性能的使用寿命预估新方法。根据劈裂强度试验和间接拉伸疲劳试验确定P0？？AC？？25（未掺加PR？？Module）和P0.5？？AC？？25（PR？？Module掺量为？？0.5%？？）的2种沥青混合料的应变疲劳方程；依托抚吉（抚州―吉安）高速公路工程，计算全年路面温度区间分布频率、全年路面轴载等级分布频率以及设计年限内不同温度区间的不同轴载等级的作用次数，并引入到计算路面结构面层层底拉应变的过程中，使拉应变更加符合路面实际情况。基于Miner疲劳累积损伤原理，计算不同温度区间、不同轴载等级下的P0？？AC？？25和P0.5？？AC？？25两种沥青混合料的疲劳累积损伤，进而得出抚吉高速公路普通沥青路面和高模量沥青路面基于疲劳累积损伤的使用寿命。研究结果表明：抚吉高速公路基于疲劳累积损伤的高模量沥青路面和普通沥青路面使用寿命分别为14.21、11.52年，故高模量沥青路面比普通沥青路面耐疲劳性能好，使用寿命约提高23.5%。以面层层底拉应变为力学指标的沥青混合料疲劳寿命预估，以及基于疲劳累积损伤的沥青路面使用寿命预估的新方法充分考虑了沥青路面结构温度区间分布和轴载等级分布，建立了较为精准的预估模型，准确描述了沥青混合料疲劳衰减的过程和规律。
In order to accurately predict the service life of the high modulus asphalt pavement, a new method for predicting the service life of asphalt pavement which considering it？？s temperature distribution, axial load distribution and fatigue performance of asphalt mixture was proposed based on fatigue cumulative damage theory. According to the split strength test and indirect tensile fatigue test, the strain fatigue equations of P0？？AC？？25 (without PR？？Module) and ？？P0.5？？？？AC？？25 (with PR？？Module content 0.5%) two kinds of asphalt mixture were determined. Based on Fuzhou to Ji？？an (Fuji) Expressway Project, the annual pavement temperature interval distribution frequency, the annual pavement axle load grade distribution frequency and function times of different axial load levels in different temperature ranges in design life were calculated, which were introduced to the process of the calculation of pavement structure surface bottom layer tensile strain, and the tensile strain was more in line with the actual road conditions.Based on Miner fatigue cumulative damage theory,the fatigue cumulative damage of P0？？AC？？25 and P0.5？？AC？？25 two kinds of asphalt mixtures under different temperature ranges and different axle loads were calculated, and then the service life of common asphalt pavement and high modulus asphalt pavement of Fuji Expressway based on the fatigue cumulative damage was obtained. The results show that the service life of high modulus asphalt pavement and common asphalt pavement of Fuji Expressway was 14.21 and 11.52 years respectively based on fatigue cumulative damage, therefore, high modulus asphalt pavement has better fatigue resistance than the ordinary asphalt pavement, and its service life is increased by 23.5%. Taking tensile strain of bottom layer as the mechanical indexes of asphalt mixture fatigue life prediction and based on the new method of cumulative fatigue damage of asphalt pavement service life prediction, which fully consider the asphalt