沥青混合料疲劳性能关键影响因素分析

从材料角度讨论了影响沥青混合料抗疲劳性能的因素,对不同因素条件下沥青混合料室内疲劳试验结果进行灰关联分析,分别研究了沥青性质、集料级配和混合料体积参数对沥青混合料疲劳模型中K值和n值影响的程度.研究表明:混合料饱和度和空隙率对K值,即沥青混合料疲劳寿命有较大影响;胶粉质量比和沥青膜厚度对n值,即疲劳寿命对应力水平变化敏感程度有较大影响.因此要提高沥青混合料耐疲劳性能,应保证沥青用量,从而形成高质量的沥青胶结料,并使混合料充分密实.

Analysis of key influential factors of asphalt-mixture fatigue property

The influential factors of asphalt-mixture fatigue property such as asphalt binds properties, gradation of aggregate, percent air voids and percent of voids filled with asphalt in asphalt mixtures are discussed. Beam flexure fatigue test results of different asphalt mixtures are analyzed by gray relation degree theory. Gray relation degree between each factor and K and n in fatigue model are studied respectively.The results show that percent air voids and percent of voids filled with asphalt in asphalt mixtures have great influence affect K value which indicates the extension of fatigue life. On the other hand, filler-bitumen ratio and asphalt film thickness primarily affect n value which indicates the stress sensitivity of fatigue life. Therefore appropriate asphalt content, high quality bitumen-filling combination and reasonable compacted density will produce preferable fatigue property of asphalt mixtures.