ABSTRACT

Loading tests were carried out on the dowel bar-concrete substructure of concrete pavement. Mechanical characteristics of dowel bar-concrete interaction were studied. In the elastic range of concrete, the bearing modulus, which is a crucial parameter but is usually determined by presumption, was calculated using classic Westergaard equations. Its influencing factors were evaluated such as concrete strength, dowel bar thickness, joint width, and anti-cohesive layer. Besides, a theoretical equation for tangential stress at the most dangerous point of concrete was deduced from Westergaard's and Timoshenko's equations. The equation reveals how the tangential stress of the most dangerous point at the dowel bar-concrete interface is affected by influencing factors. Lastly, the deterioration process of concrete around the dowel bar was revealed. The strain gauges’ data show that deterioration of concrete develops from the most dangerous point to far away from the dowel bar gradually. Two failure modes were found; one is circular spalling, the other is three main cracks. The initiation of the dowel-bar concrete structure's deterioration is circular spalling, attributed to high radial compressive stress in concrete. The deterioration starts around half the load capacity of the structure.

摘要

对混凝土路面的定位杆-混凝土下部结构进行了荷载试验。研究了定位杆-混凝土相互作用的力学特性。在混凝土的弹性范围内，承载模量是一个关键参数，但通常由假设确定，使用经典的 Westergaard 方程计算。对其影响因素进行了评价，如混凝土强度、定位杆厚度、接缝宽度和抗粘层。此外，根据Westergaard方程和Timoshenko方程，推导出混凝土最危险点切向应力的理论方程。该方程揭示了销钉-混凝土界面处最危险点的切向应力如何受影响因素的影响。最后，揭示了定位杆周围混凝土的劣化过程。应变仪的数据表明，混凝土的劣化是从最危险的位置逐渐向远离定位杆的方向发展。发现了两种失效模式；一个是圆形剥落，另一个是三个主要裂缝。销杆混凝土结构劣化的开始是圆形剥落，这归因于混凝土中的高径向压应力。恶化开始于结构负载能力的一半左右。