Design And Evaluation Of Drainage Cohesive Layer In Bridge Deck Pavement

According to large number of research, the rain often seep into the bridge deck pavement when the construction quality of pavement is not good enough. The water staying in the pavement structure may cause corrosion of the steel bar. It is a threat to the safety of the bridge structure. On the other hand, the temperture of bridges could be affected by air and sunlight cause bridges are suspended structures. From the research we found that the asphalt pavement temperture of the bridges is 5~10℃ higher than that of the road. So, under the influence of the vehicle, rain drop and high temperture, pit, lapse and rutting may appear frequently on bridge deck pavement.Improving the material properties and the construction technology is a popular approach to improve the durability of the bridge deck pavement in domestic. But using good material and good construction technology would cost more money. In order to solve this contradiction, this paper put forward a new pavement structure with drainage cohesive layer.A thin layer of open-graded friction course is used as the drainage cohesive layer on the bridge deck pavement in this paper. The structure is as follows: a waterproof layer is paved on the leveling layer of cement concrete bridge and the porous asphalt mixture is disposed over the waterproof layer which has been paved under asphalt mixture(AC-13). The Contents of this paper will provide theoretical supports and technical guidances for Anhui Jiqi Expressway project.The CAVF method is utilized to design drainage cohesive layer. And the material index of the mixture is proposed by analyzing the test result of two kinds of rock. The perfomance of the interlocked-denseness of the asphalt mixture is tested by an asphalt mixture structure type evaluating method.The asphalt mixture functional index is evaluated primarily by the laboratory experiments. The laboratory study includes observing the changes of asphalt mixture permeability in different loading duration, testing the the heat isolation effect of the drainage cohesive layer bridge.In this paper, the bond behavior between the drainage cohesive layer and concrete bridge deck is studied by the laboratory experiments. The shear property between the drainage cohesive layer and concrete bridge deck is evaluated by the symmetry shear resistance test, which is organize by the orthogonal tests mothod. The optimal method of the waterproof layer paving is proposed according to the result of the test.After proposing the design method and the material index of the drainage cohesive layer. The lower layer drainage bridge deck pavement structure with drainage cohesive layer is proved to be feasible by analyzing the test result of the laboratory experiments. At the same time, the evaluating method of the performance of the drainage cohesive layer is proposed. The evaluation method could provide reference and guidance for the future construction design of bridge deck pavement.