The Key Technology Research On The Quality Control Of Waterproof Adhesive Layer In Steel Deck Pavement In Hot And Humid Area

As an essential part of bridge deck system,bridge deck pavement plays an important role in the bridge's durability,traffic safety,traffic comfort and cost-efficiency.In addition to the pressure from traffic loading,the waterproof-adhesive layer,as a transition layer,also receives shearing and drawing effect arising from the deformation of bridge deck and pavement layer caused by temperature variation and loading.Undergoing complicated three dimensional stress,the adhesive layer is responsible for waterproofing,force-transmitting,optimizing the overall stress states,etc.As a result,the quality of the cohesive layer determines the quality of the bridge deck pavement system.Based on the Hong Kong-Zhuhai-Macau bridge project,this study investigated the waterproof cohesive layer material for steel bridge deck pavement from home and abroad as well as the bridge deck paving structure in Guangdong.After a deep analysis on the disease characteristics of the steel bridge deck pavement in Guangdong,we put forward a suitable principle aiming for the steel bridge deck pavement in hot and humid area,which can be adopted as guidance for bridge deck pavement design and construction.The performance experiment was conducted on the waterproof material MMA,including drawing,acid-and alkali-resisting and low temperature flexibility experiment,particularly designed for the waterproof cohesive layer's use conditions,performance requirements and the disease characteristics of the steel bridge deck pavement in hot and humid area.A self-made drawing fixture was applied to study the changing rule of the drawing intensity under different impact factors such as steel plate roughness,material consumption,temperature,humidity and drawing velocity,together with the rule of shearing-resisting performance under various temperature and humidity condition.The application of waterproof cohesive material in Hong Kong-Zhuhai-Macau bridge was investigated in terms of the test pavement section,and thereafter the technique guiding the construction was determined.Moreover,we obtained the key quality control technology of the waterproof cohesive material for steel bridge deck pavement.Results are presented as follows: 1)the steel bridge deck pavement diseases in hot and humid areas mainly include traction,delaminating,cracking and upheaval,which are predominantly caused by temperature and rainfall.2)Performance experiment indicators are put forward for the waterproof raw materials in hot and humid areas,and research results also reveal that thermoset waterproof cohesive materials are more favored in hot and humid areas compared with hot-melt and solvent waterproof cohesive materials.3)The drawing velocity for the combination of experiment steel plate + undercoat drawing intensity should be 50 mm/min while 10 mm/min is for the combination of experiment plate + undercoat + waterproof layer unit and steel plate + undercoat +waterproof layer + cohesive layer drawing intensity.4)The roughness of steel plate should be sandblasting polished to level III;undercoat ought to be included in waterproof cohesive system of steel bridge deck pavement and the thickness of undercoat,waterproof layer and cohesive layer should be controlled in 60 ?m,2~2.5mm and 80~120?m,respectively.5)Temperature and humidity have significant impact on the quality of waterproof cohesive system,so 25? is the best construction temperature and relative humidity should not exceed 60%.