Study On Preventive Maintenance Of Steel Bridge Deck Pavement

The surface damage appears frequently in steel bridge deck pavement (SBDP) because of environmental impact or asphalt concrete material life insufficiency. Fog seal and chip seal, widely used in preventive maintenance of asphalt pavement in the domestic and abroad, can prevent the road surface water infiltration and extend the road life, and chip seal can improve skid resistance ability of road. The fog seal and chip seal is seldom used in SBDP preventive maintenance. In view of this, fog seal and chip seal on SBDP are studied in this paper.Firstly, four performance indicators for fog seal and chip seal on SBDP are proposed according to the characteristics of SBDP surface damage. Four indicators are respectively texture depth, skid resistance performance, water seepage prevention performance and durability. Then evaluation criteria for each evaluation indicator are proposed as three categories.Secondly, research is carried out separately on fog seal and chip seal on SBDP. For fog seal on SBDP, its optimal form is determined and its performance is evaluated through the test. According to the test results, the fog seal on SBDP can effectively improve water seepage prevention performance of the epoxy asphalt and SMA pavement, but it cannot improve the texture depth and skid resistance performance of the epoxy asphalt and SMA pavement. The fog seal with sand on SBDP has good water seepage prevention performance, furthermore, it can slightly improve the texture depth and skid resistance performance of epoxy asphalt pavement. The fog seal on SBDP designed in this paper has good durability.For chip seal on SBDP,2 kinds of gradation form are proposed. One is chip seal on SBDP with single sized gravels (SCS); the other is chip seal on SBDP with graded gravels (GCS). Then the theoretic optimum dosage of gravels and epoxy asphalt are obtained by empirical formula. According to the test results, two kinds of chip seal on SBDP can improve surface skid resistance ability of the epoxy asphalt pavement, and can make up for the lack of texture depth. GCS has a lower ratio of water seepage coefficient than SCS, but neither SCS nor GCS can improve the water seepage prevention performance of the epoxy asphalt pavement. The combination seal structure on SBDP (CSS), formed by the combination of GCS and fog seal, can make up for the lack of texture depth, improve skid resistance performance and water seepage prevention performance of SBDP. CSS also has good durability.At last, the SBDP preventive maintenance timing methods and key construction technology are studied. The SBDP preventive maintenance timing can be determined by method of benefit cost ratio. The timing of chip seal on epoxy asphalt pavement should be about the aging of SBDP nearly used for 41～63 months.In fog seal construction process, special machinery should be used and spraying quantity of fog seal materials should be monitored. In chip seal construction process, spraying quantity of gravel and epoxy asphalt should be monitored. Standard for construction quality acceptance is proposed according to the research results.