水泥混凝土路面沥青加铺层板缝弯沉差指标的试验研究

Laboratory Research on the Deflection Difference between Two Slabs of the Concrete Pavement under Asphalt Overlay

车辆荷载作用所引起的剪切破坏是旧混凝土路面上沥青加铺层结构产生反射裂缝的主要原因之一，设计中可以用板缝弯沉差这一指标予以控制。通过室内足尺试验，研究了沥青加铺层对混凝土板接逢弯沉差的影响，并使用大型疲劳设备，研究了弯沉差随荷载作用次数变化的规律，其结果可为以弯沉差为指标的设计方法提供依据。

Reflection cracking is one of the conventional damage in asphalt concrete (AC) overlay on the existing Portland cement concrete (PCC) pavement, which is resulted from shear stress induced by vehicle load. The deflection difference at the joints between two slabs can be used to control this mode of distress. In this paper, the effect of AC overlay on the deflection difference is analyzed through the tests on full size model as well as the comparison of data before AC surfacing with those after surfacing. Using large scale test equipment, the fatigue response and property of this structure is also studied under repeated loads. The research results present in the paper can be applied to the design procedure of AC overlay on the existing PCC pavement.