Study On Waterproof And Cohesive Layer Of Asphalt Concrete Pavement For Cement Concrete Bridge Under The Condition Of Warm-wet And Heavy Load

In recent years,the development of highway industry in our country is rapid,and the bridge plays a very obvious role in construction and operation of highway as an important part of the highway network.The bridge deck pavement is an important part of the bridge,and the quality of the bridge,the safety and durability of the bridge and the economic benefits are related to the quality of the bridge.The waterproof adhesive layer has a very important role as a part of the bridge deck pavement,not only connect cement bridge deck and asphalt concrete surface layer as an integrated whole through their own bond,but also resist water erosion inside a bridge with good impermeability to protect the bridge panel.In order to ensure the pavement performance of bridge deck pavement,it is necessary to study the performance and selection of waterproof adhesive layer.In this paper,the basic performance and road performance of the waterproof adhesive layer material will be in-depth study based on the climate of Guangdong Province which is humid and rainy and combined with lab experiments and theoretical analysis.After the results were compared and analyzed,the cement concrete bridge deck waterproof bonding layer material will be optimized for Guangdong province to used.This study detect the basic properties of waterproof adhesive layer material and forming composite specimens through the investigation of Guangdong highway bridge deck disease,and obtained the following research results through a series of laboratory tests:1.The basic performance on AMP-100,FYT-1,SBS modified asphalt and modified asphalt waterproofing materials are qualified such as the solid content,heat resistance,bonding strength and tensile strength.The four kinds of basic performance index of materials are in line with the "Waterproofing coatings for concrete bridge and road surface."(JC/T 975-2005).2.The shear strength of waterproof material was evaluated by means of laboratory shear test under different temperature,shear rate and interface treatment.The results show that the SBS modified asphalt has the best shear strength in high temperature,and it is suggested that the shear strength at 65 degrees in Guangdong province is the standard to evaluate the high temperature resistance of waterproof materials;3.The pullout resistance of waterproof material was evaluated by means of laboratory indoor pullout test under different temperature and soaking conditions.The waterproof material tensile strength decreases gradually with the increase of temperature at the same temperature,the drawing performance is as follows: SBS >AMP-100>FYT-1> modified asphalt emulsion.The drawing strength of the materials after immersion in water was significantly lower than that in none immersed specimens.4.The interlaminar shear stress and normal tensile stress of bridge deck pavement structure model are analyzed by ABAQUS.The study found that,when the vehicle axle load is doubled,the transverse interlaminar shear stress is maximum increased to 1.72 times,the longitudinal interlaminar shear stress is maximum increased to 3.04 times and the maximum increase of normal tensile stress between layers is 2.52 times that of the original one.The analysis can be carried out that the maximum shear stress is 0.39 MPa and the maximum normal tensile stress is 0.21 MPa under different working conditions.It is suggested that the shear strength of the waterproof material should be not less than 0.45 MPa and the tensile strength shall not be less than 0.3MPa at 25 degrees in Guangdong province.The thickness of waterproof layer does not change effect of shear stress between layers,so it is suggested that the thickness of the construction area in Guangdong province of the waterproof layer is 3mm,the best waterproof layer modulus is 100~200MPa.5.The key technology of waterproof adhesive layer for waterborne coatings was studied.At last,the shear performance,drawing performance and economic benefit of several kinds of materials are compared and analyzed and optimized for the best waterproof material used in Guangdong is SBS.