Mechanical characteristics of dowel bar-concrete interaction: based on substructure experiment

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.

Automated summary

Loading tests were conducted on the dowel bar-concrete substructure of concrete pavement to investigate the mechanical characteristics of dowel bar-concrete interaction. The study calculated the bearing modulus and deduced a theoretical equation for tangential stress at the most dangerous point of concrete. Additionally, the deterioration process of concrete around the dowel bar was revealed, showing two failure modes.