基于数字散斑相关技术的沥青混合料老化特性实验研究

Aging characteristic test research of asphalt mixture based on the digital speckle correlation method

基于数字散斑相关技术DSCM(digital speckle correlation method),利用VIC-3D(video image correlate-3D)图像处理系统,通过半圆弯拉实验(semi-circular bending test,简称SCB实验),对温度老化前后的SBS改性沥青混合料和橡胶粉(CR)改性沥青混合料半圆试件的三点弯拉实验从加载到破坏的全过程进行图像采集,利用VIC-3D计算软件计算半圆试件全过程的水平应变、水平应变速率并通过荷载-位移曲线求出的断裂能指标,研究沥青混合料老化特性。结果表明,数字散斑相关技术,作为一种非接触、非干涉、全场变形的光学计量方法,可以很好地应用于沥青混合料的老化特性研究;在半圆试件从加载到开裂破坏的全过程中,温度老化后的沥青混合料的持荷能力和抵抗开裂破坏的能力与老化前相比明显削弱;温度老化后的CR改性沥青混合料比温度老化后的SBS改性沥青混合料有更好的抗裂性能。

Based on the digital speckle correlation method(DSCM),using the VIC-3D(video image correlate-3D)image processing system,by semi-circular bending test(SCB Test),the images of the SBS modified asphalt mixture and rubber powder(CR)modified asphalt mixture that before and after temperature age are acquired in the whole process from the load to the crack destruction,VIC-3Dcalculation software was used to calculate the horizontal strain,horizontal strain rate of the semicircle specimen and through load-displacement curve and the fracture energy index to study the aging characteristics of the asphalt mixture.The results show that:the digital speckle correlation method,as a kind of non-contact,non-interference,the whole deformation optical measurement method,can study the aging properties of asphalt mixture very well;in the whole process from the load to the fracture,compared to the non-aged asphalt mixture,the load holding ability and crack resistance of the temperature aged asphalt mixture obviously weakened;the CR modified asphalt mixture after temperature age has better crack resistance than the SBS modified asphalt mixture after temperature age.