Research On Properties Of Several Waterproof And Cohesive Layers For Concrete Bridge Deck

The quality of the waterproof adhesive layer in concrete bridge has great effects on the duration of bridge structure directly. Engineers begin to attach more and more importance to how to choose proper material and design well waterproof adhesive layer. Now, a great deal of work has been done for deck paving design of the long-span steel bridge in the fields of numerical simulation, material application, interlay waterproof adhesive layer and so on. Although some research productions have been gained already, there is little work on waterproof adhesive layer of many concrete bridge decks. The results from the present investigation suggest that the early damage of concrete bridge deck is directly relevant to the performance of waterproof adhesive layer. The profound research on the properties of waterproof adhesive layer in concrete bridge deck is significant for the application of it in practical projects.On the basis of research on status of waterproof adhesive layer at home and abroad, micro rubber powder modified asphalt was prepared in the paper .To confirm the influence of preparing time, preparing temperature and addition of modifier, the penetration degree, ductility and soft point were determined and investigated. The results showed that favorable modified asphalt could be obtained under conditions of addition 12%, shear time 60min, shear temperature 200℃. Dynamic Shear Rheometer was chosen to conduct the researches on the complex modulus and phase angle of micro rubber powder modified asphalt and the results indicated that the modified asphalt with addition of 12% had the best comprehensive performance in low and high temperature.Additionally, the shear strength and tensile strength of three type of the waterproof adhesive material making up of AH-90 asphalt, SBR emulsified asphalt, and micro rubber powder were studied at different concentrations, temperatures, and surface modification methods. The results showed that the shear strength of SBR emulsified asphalt had a maximum value at high (60℃) and room (25℃) temperature. The shear strength of micro rubber powder modified asphalt was the largest one in three materials at low (0℃) temperature. After freeze-thaw cycle, SBR emulsified asphalt had the largest shear strength value, and the shear strength ratio variation of micro rubber powder was the lowest. And the shear strength of the adhesive layer decorated by artificial chiseling was largest, steelwire brush scuffing second and original surface lowest. The tensile testing results showed that SBR emulsified asphalt had the largest tensile strength and layer decorating had little influence on tensile strength.Research on the fatigue life of shearing resistance of three waterproof adhesive materials was carried out using Universal Servo Hydraulic Testing Machine (UTM). The results showed that the fatigue resistance of SBR emulsified asphalt were the best one at room temperature. But the fatigue resistance of micro rubber powder modified asphalt was better than SBR emulsified asphalt at low temperature. The phenomenological fatigue methodology was applied and the fatigue life versus stress equations of bridge deck waterproof adhesive layer was constructed in low (0℃) and room (25℃) temperature to supply reliable basis for the fatigue life predication of the bridge pavement structure.