| Popis: |
Durability of concrete on bridges has been widely investigated over the past decades. Most of the studies focus on monolithic concrete without considering the effect of joints (e.g., direct wet joint; roughened wet joint; dry joint; epoxied joint) caused by various construction methods. However, in recent years, researchers have found that joints have a certain impact on the durability of concrete on bridges. This paper reviews and discusses the findings of Tongji University on the durability of joints in concrete bridge structures. On the basis of results of many durability experiments that simulate construction processes, joints may be the weak link of the concrete durability on bridges. The mortar layer and construction measures at the joint zones result in a special microstructure of concrete, which is the main reason of the weakness. In addition, some factors affecting the durability of joints are reviewed, including the concrete strength, joint types, and load conditions. These factors show different impacts on chloride ion penetration, carbonation and frost corrosion at the joint zones. Finally, some potential research directions for future are suggested. |
