泡沫沥青冷再生混合料成型方法  

Research on the compaction methods of cold recycled mixture using foamed asphalt

作　　者：李志刚[1] 郝培文[2] 曾志武 

机构地区：[1]长安大学公路学院,西安710064 [2]长安大学道路结构与材料交通行业重点实验室,西安710064

出　　处：《复合材料学报》2017年第9期2038-2046,共9页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51278060;51408050)

摘　　要：采用振动成型设备以压实度为指标确定了泡沫沥青冷再生混合料振动成型的振动时间。振动成型、静压成型、马歇尔成型及旋转压实成型试件在总空隙率相同的条件下,对比了不同成型方法混合料的力学强度,分析了强度差异产生的原因。基于CT检测手段,分析了不同成型方法混合料内部空隙分布状态、空隙分形维数、最可几孔径及平均孔径。结果表明:旋转压实的"揉搓作用"显著增大了冷再生混合料的间接拉伸强度,振动成型次之,静压成型与马歇尔成型混合料间接拉伸强度(ITS)较接近,而四种成型方法混合料的无侧限抗压强度差别不大;旋转压实及振动成型会影响泡沫沥青冷再生混合料内部细颗粒的分布,进而影响混合料内部空隙的分布状态,这两种成型方式混合料内部空隙数目多且等效半径小。不同压实方法的压实机理的差异导致混合料内部空隙平均孔径、空隙维数及最可几孔径存在差异。空隙特征的不同是引起冷再生混合料力学强度差异的本质原因。Vibratory time was determined by compaction degree index using simple vibratory compaction equipment.The strength of different compaction methods were measured while the void volume of all the specimens kept approximate consistent.Then,the difference of 4kinds of compaction methods was compared and the results were analyzed.The air void distribution,fractal dimension,the most probable diameter and average diameter was conducted by using CT scanning.Test results show that the＂kneading effect＂of SGC has a significant influence on ITS of cold recycled mixture using foamed asphalt（CRMF）and vibratory compaction takes the second place.However,ITS of the specimens manufactured by static compaction and Marshall compaction methods have little difference;And the UCS of four kinds of compaction methods get little difference;The distribution of fine particles is affected by using SGC and vibratory compaction methods.Thus,the air void distribution is affected by the change of fine particles distribution.The number of air voids is larger and the equivalent diameter of air voids is smaller compared with static and Marshall compaction methods.Difference of compaction mechanism between compaction methods leads to the difference of characteristics（fractal dimension,the most probable diameter and average diameter）of air void.The different characteristics of air voids,in essence,make mechanics strength of CRMF different.

关 键 词：振动成型 不同压实方法 力学强度 空隙分布状态 空隙特性 

分 类 号：TB332[一般工业技术—材料科学与工程]