基于CT技术沥青混合料集料的识别与分离

Identification and Separation of Aggregates in Asphalt Mixture Based on Computed Tomography

为了研究沥青混合料内部集料结构,利用CT断层扫描技术对沥青混合料内部集料进行三维重构,基于Matlab(自行编制程序对集料进行识别与分离。很多情况下集料是互相接触的,这些相互接触的集料容易被程序错误地识别成是一个集料。为此首先用Gaussian过滤器使集料变得更光滑,再利用Hmax过滤器使集料变得更平滑,最后进行Watershed过滤器把连接在一起的集料截段进行识别与分离。通过不同试验对这一方法进行了论证。基于此,利用CT断层扫描分析实际的沥青混合料。从计算出来的集料体积信息可以看出,与混合料内部集料级配情况是相符的。研究结果表明基于CT技术沥青混合料集料的三维识别与分离是可行的,为进一步研究沥青混合料压实过程中集料运动方向、离析和级配变化等打下了坚实的基础。

In order to study the aggregates structure within asphalt mixture,the 3D aggregate structure was reconstructed based on CT technology.The program based on Matlab was developed to conduct aggregate identification and separation.Most of the time,the aggregates which touch each other are easily be identified as one aggregate.Therefore,the Gaussian filter was used to smooth the aggregates,Hmax filter was used to flat the aggregates,and Watershed filter was applied to cut the touched aggregates.The technique was validated by laboratory experiments.Based on this technique,the real asphalt mixture was analyzed based on CT slices,and the calculated aggregate volume information was consistent with the grading information.The results reveal that it is feasible to identify and separate the aggregates within asphalt mixture based on CT technology,which is good for the research of aggregate orientation,segregation and gradation change during the compaction.