摘要
采用数字散斑相关技术对橡胶粉(CR)改性沥青混合料和苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)改性沥青混合料进行变形场分析,利用Vic-3D图像处理软件对散斑图像进行处理,提取试件表面随着荷载变化的位移场和应变场.通过预切口半圆弯拉实验研究沥青混合料的断裂韧性.结果表明:水平位移变化速率和水平应变适用于沥青混合料裂纹性质及断裂特性的分析.在沥青混合料裂纹开裂过程中,开裂时的荷载、最大荷载与最大水平应变对应荷载并非同一荷载值.与SBS改性沥青混合料相比,长期温度老化和冻融循环前后,CR改性沥青混合料都具有更强的抗开裂能力,并且长期温度老化对2种改性沥青混合料影响较大.通过分析断裂韧性指标得到与DSCM实验结果相吻合的开裂特性,验证了DSCM对沥青混合料裂纹研究的适用性.
The deformation fields of crumb rubber(CR)modified asphalt mixture and styrene-butadienestyrene(SBS)modified asphalt mixture were analyzed and compared by using digital speckle correlation method(DSCM).Vic-3Dimage manipulation software was applied to analyze speckle images.Deformation field and strain field of the samples' surface that changed along with load were extracted.Fracture toughness of the asphalt mixture was studied through pre-cut semi-circle flexural tensile test.Results show that the change rates of horizontal displacement and the horizontal strain are suitable for the analysis of the crack properties and fracture characteristics of asphalt mixture.The micro-crack initiation load,the maximum load and the maximum horizontal strain are not the same load value.Compared with the SBS modified asphalt mixture,the CR modified asphalt mixture has stronger ability to resist cracking before and after long-term aging and freeze-thaw cycle.The long-term temperature aging of asphalt mixture has greater impact on the two kinds of modified asphalt mixture.The cracking characteristics from analysis of fracture toughness index agree with the experimental results of DSCM,indicating that DSCM is suitable for research on crack in asphalt mixture.
出处
《浙江大学学报(工学版)》
EI
CAS
CSCD
北大核心
2015年第9期1805-1811,共7页
Journal of Zhejiang University:Engineering Science
基金
国家自然科学基金资助项目(11162012)
关键词
沥青混合料
数字散斑相关法
半圆弯拉实验
变形场
断裂韧度
asphalt mixture
digital speckle correlation method(DSCM)
semi-circular bending test
deformation field
fracture toughness