粗集料接触配位参数影响下沥青混合料的抗断裂特性研究  

Fracture Resistance of Asphalt Mixtures Under the Effect of the Coordination Number of Particles Contact Forces of Coarse Aggregates

作　　者：牛冬瑜[1] 黄山 师伟博 谢希望 汪严 高仰明 NIU Dongyu;HUANG Shan;SHI Weibo;XIE Xiwang;WANG Yan;GAO Yangming(School of Materials Science and Engineering,Chang’an University,Xi’an 710061,China;Zhejiang Scientific Research Institute of Transport,Road Engineering Research Institute,Hangzhou 310012,China;Jiangsu Sobute New Materials Co.,Ltd.,State Key Laboratory of High-Performance Civil Engineering Materials,Nanjing 211103,China;School of Civil Engineering and Built Environment,Liverpool John Moores University,Byrom Street,L33AF,Liverpool,United Kingdom)

机构地区：[1]长安大学材料科学与工程学院,西安710061 [2]浙江省交通运输科学研究院道路工程研究所,杭州310012 [3]江苏苏博特新材料股份有限公司高性能土木工程材料国家重点实验室,南京211103 [4]利物浦约翰摩尔大学土木工程与建筑环境学院,英国利物浦Byrom Street,L33AF

出　　处：《材料导报》2024年第23期58-67,共10页Materials Reports

基　　金：中央高校基本科研业务费专项资金资助(300102314902);陕西省自然科学基础研究计划资助项目(2024JC-YBMS-374);国家自然科学基金(51608045)。

摘　　要：为探究细观骨架优化对沥青混合料抗断裂性能的影响,研究了细观尺度下主骨架粗集料的接触特性与沥青混合料抗断裂性能的关系。基于颗粒堆积理论与细观接触力学,修正了表征主骨架结构细观接触特征的粗集料接触配位参数(C_(npcf)),并设计了九种具有不同细观结构的级配。基于半圆弯试验(SCB)确定了合理的抗断裂性能评价指标,采用Python编程实现SCB试验后试件表面的数字图像协同处理,在细观尺度探究了不同C_(npcf)下断裂扩展的规律。最后,根据灰熵理论,综合分析了不同结构特征参数与断裂性能的灰关联性。结果表明,沥青混合料的强度、能量指标,随着C_(npcf)增加呈现先增后减的趋势。当C_(npcf)=7.35时,沥青混合料的抗断裂性能(σm=1.18 MPa,G f=3003.4 J/m 2,CRI=509.1)更优。随着加载位移的增加,裂缝面积和长度呈线性扩展,但在不同C_(npcf)下显著开裂时的加载位移并不一致。控制C_(npcf)于7.2~7.6之间,将能有效增强混合料抵抗断裂扩张的能力。不同温度条件下C_(npcf)在能量和强度层面与抗断裂性能均具有强灰关联,这为在细观结构尺度优化沥青混合料性能提供了新思路。To investigate the impact of mesoscale skeleton optimization on the fracture resistance of asphalt mixes,the relationship between the contact behaviors of coarse aggregates on the dominant skeleton and the fracture resistance of asphalt mixes at the mesoscale was studied.Based on the particle accumulation theory and mesoscale contact mechanics,the coordination number of particles contact force(C_(npcf))for coarse aggregates was modified to characterize the mesoscale contact characteristics in the dominant structure.And nine kinds of asphalt mixes with diffrent meso-structural garadations were designed.Appropriate fracture resistance evaluation criteria were identified based on the semicircular bending test(SCB).Co-processing for digital images on specimen surfaces after the SCB test was implemented by Python programming,and the regularity of fracture extension with varied C_(npcf)was explored at the mesoscale.Finally,the gray correlation between various structure characteristic parameters and fracture performance was comprehensively analyzed according to the gray relational analysis and entropy theory.The results indicated that the strength and energy indicators of the asphalt mixture exhibited the trend of increasing and then decreasing with the increase of C_(npcf).When C_(npcf)eaquals to 7.35,the asphalt mixture has better fracture resistance(σm=1.18 MPa,G f=3003.4 J/m 2,CRI=509.1).Moreover,the crack area and length expands linearly with the increasing of loading displacement,but the loading displacement was not consistent for notably appeared cracks appeared under varying C_(npcf).Thus,the capacity of the mix resisting fracture dilation will be enhanced by restricting the C_(npcf)between 7.2 and 7.6.Significant gray correlations of C_(npcf)with fracture resistance on both energy and strength levels were observed under distinct temperature conditions,which provides new perspectives for optimizing asphalt mixture performance at mesoscales.

关 键 词：道路工程 沥青混合料 抗断裂性能 细观结构优化 颗粒堆积理论 数字图像处理 

分 类 号：U414[交通运输工程—道路与铁道工程]