中文摘要：

开裂是钢桥面铺装层的主要破坏形式。为研究钢桥面沥青混合料断裂特性及裂纹扩展规律,通过小梁三点弯曲实验,应用数字图像相关方法（DIC）图像采集系统采集试件从加载到破坏的全过程图像。利用非接触式全场应变测量系统（VIC-2D）计算试件在加载过程中的位移场和应变场,并分析出裂缝萌生、发展的规律。结果表明：沥青混合料从相对较弱的胶浆区或胶浆-粗集料界面区开裂和发展;当胶浆-粗集料界面与裂纹发展方向垂直时,粗集料对裂纹的发展有阻断作用;胶浆裹覆细集料的运动轨迹与胶浆的运动轨迹一致。

英文摘要：

Cracking is the main form of damage to steel deck.In order to study the steel bridge asphalt mixture properties crack propagation law by three-point bending test,the paper used DIC image acquisition system to collect image of the whole process from loading to break of the specimens.Furthermore,the crack initiation and development of the law was analyzed by VIC-2Dcalculation specimens during the loading process of displacement and strain fields.The results showed that：asphalt mixture cracking and development start from relatively weak glue or glue area-coarse aggregate interface zone.When the glue-coarse aggregate interface is perpendicular to the crack development direction,coarse aggregate can block the development of crack.The trajectory of fine aggregate covered with asphalt and the trajectory of asphalt cement is consistent.