基于沥青路面分析仪疲劳试验，通过调整试件的宽跨比来增强试件尺寸对路面结构的代表性，研究沥青混合料板式试件的疲劳开裂规律．制备原状、短期老化和长期老化3 种板式试件，用往复移动的试验轮加载，使对边简支的板式试件内产生双向弯拉应力，测量疲劳过程中的挠度变化，观察裂缝开展过程，测定试件破坏时的疲劳寿命．板式试件疲劳试验显示了具有初始局部缺陷的有限宽度板在双向弯拉应力下的开裂过程．板底裂缝既呈现出从下至上的垂直扩展，又在板底水平方向呈现出长度的增加．板式试件的裂缝发展、裂缝形态及挠度变化均有别于梁式试件．

The fatigue cracking law of asphalt mixture slabs is investigated based on the APA ( Asphalt PavementAnalyzer) fatigue test,and the representativeness of specimen geometry to actual pavement structure is improved byadjusting the width-span ratio of asphalt mixture specimens. In the investigation,first,unaged,short-term agingand long-term aging slab specimens are respectively fabricated and loaded with a cyclic moving wheel to generatebidirectional bending stress in the opposite-edge supported slab. Then,the deflections of the specimens are measured,the development of fatigue crack is observed,Finally,the fatigue life of specimen is determined at the time itfails.By these fatigue tests,the cracking propagation of a finite-width slab with inherent local defects and underbidirectional bending stress is revealed.The results indicate that the crack tip vertically propagates from the slabbottom to the top and presents a length increase in the horizontal direction at the bottom,and that the crack development,the crack pattern and the deflection curve of the slab specimens are all different from those of beam specimens.