基于单轴贯入试验的AC-20级配优化  

AC-20 Gradation Optimization Based on Uniaxial Penetration Test

作　　者：高振鑫[1] 李强[2] 蒋应军[2] 刘根昌 

机构地区：[1]陕西省交通运输厅,陕西西安710075 [2]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064 [3]许昌市建设投资有限责任公司,河南许昌461000

出　　处：《中国公路学报》2017年第4期24-31,共8页China Journal of Highway and Transport

基　　金：河南省交通运输厅科技项目(2014K49-1)

摘　　要：为了提高沥青混合料的路用性能,利用颗粒流软件PFC^(2D)构建了沥青混合料单轴贯入数值试验方法,阐述了沥青混合料单轴贯入数值试验中试验条件的模拟方法和模型参数的取值,结合实体工程中AC-20室内单轴贯入试验评价了其可靠性。选取不同的原材料得到3组模型参数,基于单轴贯入数值试验研究了模型参数取值、粗集料级配、细集料级配和粗细集料比例对沥青混合料抗剪强度的影响规律。最后,通过室内单轴贯入试验确定了关键筛孔最佳通过率范围,提出了以抗剪强度最大为原则的AC-20矿料级配,并验证了其路用性能。结果表明:单轴贯入强度模拟曲线与室内实测曲线基本吻合;单轴贯入数值试验模型参数的取值对最大抗剪强度时集料的比例不产生影响;五档粗集料19~26.5mm,16~19mm,3.2~16mm,9.5~13.2mm,4.75~9.5mm的比例为3∶12∶5∶10∶10,细集料级配取I=0.75时所对应的级配,粗细集料比为60∶40时,沥青混合料抗剪强度最大;建议AC-20沥青混合料矿料级配9.5mm,4.75mm,2.36mm及0.075mm筛孔通过率分别为50%~60%、34%~44%、31%~37%和3%~7%;与规范推荐级配中值相比,优化级配AC-20混合料的抗剪强度、动稳定度分别提高了25%、27%。In order to improve the road performance of asphalt mixture, a numerical uniaxial penetration test method of asphalt mixture was established by the particle flow software PFC2D. The simulation method of the asphalt mixture numerical uniaxial penetration test conditions and the parameters of the model were described. The reliability of this method was verified by AC-20 indoor uniaxial penetration test in the practical engineering. Three different model parameters were selected by different raw materials. Influence law of model parameters, coarse aggregate gradation, fine aggregate gradation and coarse aggregate ratio on shear strength of asphalt mixture were investigated on the basis of numerical uniaxial penetration test. Finally, the optimum pass rate range of the key sieve was determined by the indoor uniaxial penetration test. The AC-20 aggregate gradation with the maximum shear strength was proposed, and its road performance was verified. The results show that the simulation curves of uniaxial penetration strength are basically consistent with the measured curves of indoor test. The model parameters of the numerical uniaxial penetration have no effect on the proportion of aggregate in the maximum shear strength. The ratio of coarse aggregates of 19-26.5 mm, 16-19 mm, 3.2-16 mm, 9.5-13.2 mm and 4. 75-9. 5 mm is 3 ： 12 ： 5 ： 10 ： 10. When the I value of fine aggregate gradation is 0.75, the proportion of coarse aggregate and fine aggregate is 60 ： 40 with maximum shear strength of asphalt mixture. It is suggested that the pass ratios of AC-20 asphalt mixture gradation of 9. 5 mm, 4. 75 mm, 2. 36 mm and 0. 075 mm are 50%-60%, 34%-44%, 31%-37% and 3%-7%respectively. Compared with the standard grade, the shear strength and the dynamic stability of the AC-20 mixture with gradation optimization increase by 25% and 27%respectively.

关 键 词：道路工程 级配优化 数值试验 沥青混合料 颗粒流 

分 类 号：U416.217[交通运输工程—道路与铁道工程]