CAJ | 학술논문

量化研究了沥青混合料冻融劈裂试件微观结构的损伤特性.基于冻融劈裂前后试件的CT图像,以CT值和损伤变量为基础,根据试件内部损伤特征,借助损伤力学基本概念,通过适当的数学假设,建立了冻融劈裂前后沥青混合料试件内部结构CT值分布规律的数学模型.利用CT值和损伤变量实现了对冻融劈裂前后试件内部微观损伤的量化.以损伤力学概念为基础,给出了沥青混合料损伤密度的定义,推导了以CT值表示的混合料密度损伤变量表达式,从而将CT值和损伤变量联系起来.利用损伤变量可以对混合料试件冻融劈裂前后内部微观结构的变化进行对比分析,实现了试件内部微观损伤特性变化的定量对比.对冻融劈裂前后试件上中下3个层位损伤变量的计算结果表明,冻融劈裂后试件各层位相应的损伤变量均有不同程度的增加,与CT图像表明的试件内部损伤明显加剧相吻合.
양화연구료력청혼합료동융벽렬시건미관결구적손상특성.기우동융벽렬전후시건적CT도상,이CT치화손상변량위기출,근거시건내부손상특정,차조손상역학기본개념,통과괄당적수학가설,건립료동융벽렬전후력청혼합료시건내부결구CT치분포규률적수학모형.이용CT치화손상변량실현료대동융벽렬전후시건내부미관손상적양화.이손상역학개념위기출,급출료력청혼합료손상밀도적정의,추도료이CT치표시적혼합료밀도손상변량표체식,종이장CT치화손상변량련계기래.이용손상변량가이대혼합료시건동융벽렬전후내부미관결구적변화진행대비분석,실현료시건내부미관손상특성변화적정량대비.대동융벽렬전후시건상중하3개층위손상변량적계산결과표명,동융벽렬후시건각층위상응적손상변량균유불동정도적증가,여CT도상표명적시건내부손상명현가극상문합.
The purpose of the study is to quantify the micro structure damage characteristics of the freeze-thaw split specimens of asphalt mixture.Based on the original CT images of specimens and CT images after the freeze-thaw split test,and also based on the basic concepts of damage mechanics,the mathematic distribution models of CT values of the freeze-thaw split specimens were constructed by using CT value and damage variable and suitable mathematic assumption according to its inner damage characteristics.Then,the quantification of micro damages before and after freeze-thaw split test were perform by utilizing CT values and damage variables.On the basis of concepts of damage mechanics,the definition of damage density of asphalt mixture was given and a damage density formula expressed by CT value for asphalt mixture was derived.In this way,the CT value and damage variable were connected.The damage variable can be utilized to contrast and analyze the inner micro structure change of asphalt mixture specimens before and after freeze-thaw split test.Therefore,the damage characteristic changes inside the specimens can be quantified.The calculation results of upper,middle and lower scanning sections of freeze-thaw split specimens show that the damage variables of each section in the specimens are all increased to certain degree after the freeze-thaw split test.The increases inosculate the apparent aggravation of damage inside the specimens reflected by CT images.