Study On The Synthesis And Properties Of High Strength And High Permeability Waterproof Material For Bridge Deck

Waterproof adhesive layer is an important part of the bridge deck pavement structure.A large number of studies have shown that the installation of the waterproof and adhesive layer is very important to ensure the quality and safety of the cement concrete deck.The premature failure of a large number of bridge deck pavements in China is closely related to the choice of materials and the design of the waterproof adhesive layer,which is due to the fact that the theoretical research and construction technology research on the waterproof adhesive layer in China is not comprehensive enough to solve this problem.The important means of the problem is to conduct more in-depth research on the material and comprehensively analyze it from the perspective of mechanics,which is of great significance for improving the paving technology of the waterproof adhesive layer of the bridge deck.In this paper,the ABAQUS finite element analysis software is used to simulate and calculate the physical behavior of No.2 Bridge of Nandao High-speed Power Station Bridge under moving load,and the variation law of the maximum shear stress at the middle point of the middle wheel track of the waterproof and adhesive layer with time is obtained.Furthermore,the maximum shear stress is used as a control index for the experimental study of indoor material properties.Meanwhile,the calculation parameters of each structural layer are changed to obtain the variation rule of each stress distribution over time.The results show that the maximum shear stress of the waterproof layer is significantly affected by overload,brake and slope gradient.The maximum shear stress of the waterproof adhesive layer is negatively related to the thickness of the asphalt layer and the vehicle speed.The thicker the asphalt pavement,the faster the vehicle speed.The smaller the shear stress in the waterproof layer is,the smaller the asphalt layer modulus is.The effect of the change on the maximum shear stress in the waterproof layer is not obvious.In the actual running of the vehicle,the maximum shear stress in the waterproof layer appears directly below the wheel.Through the calculation and analysis of the combination of overload,brake and vertical slope,two indexes are put forward as the basis for detecting of the performance of waterproof materials.A study was conducted on waterproof adhesive layer materials,and ten types of waterproof adhesive materials were prepared using the principles of similar compatibility and other polymer theories.The preparation process of the material,which includes the hot melt method and the room temperature method,was compared and analyzed.Also,the properties of low temperature flexibility,heat resistance,water impermeability,and adhesion strength were compared.The results show that the material prepared at room temperature is safe,simple,and non-polluting,and suitable for large-scale industrial production;the adhesion strength of formula A5 is significantly better than other types,whose low temperature flexibility,impermeability and other indicators meet the specification requirements.Through comparison and selection,A5 which owns the best overall performance was selected as the best formula for high-strength and high-permeability bridge waterproof material.Then,a systematic comparative study of the high-strength and high-permeability A5-type waterproof adhesive material,SBS-modified emulsified asphalt,and SBS modified asphalt was conducted through laboratory tests to determine the various materials.The optimum amounts of shear strength and tensile strength were used,and the effects of temperature,interface treatment,freeze-thaw and other factors on the shear strength and tensile strength were further analyzed at the optimum dosage.The test results show that the shear strength and tensile strength of A5 type waterproof adhesive material are far superior to the other two materials at room temperature,and the shear strength and drag reduction after freezing-thawing are smaller,and the residual strength is the highest;Increasing the depth of construction of bridge panel helps to improve the shear strength and tensile strength;all three materials have good anti-construction damage performance and meet the requirements.Finally,on the basis of a large number of laboratory experiments,combined with practical engineering like Nandao High-Speed,the construction technology of waterproof materials for high-strength and high-permeability bridge decks has been studied,the construction processing has been improved,and the corresponding construction quality control standards have been proposed.