Experimental Research On Viscoelastic Damping Material And Damping Performance Of Pavement Constraint Damping Structures

The problem of road vibration caused by vehicle driving has become a serious environmental problem.How to control the road vibration caused by traffic will become an important research direction and arouse more and more social attention.In this paper,viscoelastic damping materials(their grades are Qtech-T502 and Qtech-413S)are used as damping layer in road vibration reduction,the road base as the base,the asphalt concrete as the constraint layer,and the pavement restraint damping structure is formed.The influence of damping layer material and damping layer thickness on damping performance of pavement constrained damping structure is studied by single point hammer test.This paper studies the characterization of the conventional and damping properties of the two viscoelastic damping materials,and designs environmental simulation experiments based on the application environment of damping materials,including wet and dry cyclic tests and high and low temperature cyclic tests,According to the construction of a bridge in Qingdao,the construction technology of the restrained damping structure of pavement is established.Firstly,the environmental simulation experiment is designed with Qtech-T502 viscoelastic damping material as an example,After 160 wet and dry cycles,the tensile strength of the material was stable at 0.94MPa,with a decrease of 33.6%.The tearing strength stabilized at 4.10KN/m,the decrease was 22.37%.The elongation of fracture was stable at 340%,the descent was 33.6%,and the tensile strength of the material was 0.92MPa after 160 cycles of high and low temperature,the descent range is 9.71%.The elongation rate of rupture was stable at 306.21%,and the decrease was 44.81%.Tearing strength was 4.05KN/m,decreased by 23.87%.When the frequency is fixed,the loss modulus of the material increases with the increase of temperature and then decreases,and the glass transition of the material Vinvic to-20??40?.When the temperature is constant,the loss modulus and loss factor peak and the corresponding temperature are increased with the increase of the frequency,the loss factor from 1Hz to 100Hz,the loss factor peak from 0.427 to 0.606,the peak temperature from 62? to 96?.Secondly,the influence of damping material and thickness of damping layer on damping performance of pavement constrained damping structure is studied.Research results show that,When the damping material adopts qtech-T502 viscoelastic damping material,qtech-413S viscoelastic damping material and epoxy treatment,the 1th order natural frequency change is very small.The 2-order natural frequencies were significantly reduced and 1-2-order composite loss factors increased.The 2-order natural frequencies were significantly reduced and 1-2-order composite loss factors increased.2)Thickness of damping layer,the thickness of damping layer takes 1mm,1.5mm,2mm,3mm,In lmm-2mm,increasing the thickness of the damping layer can reduce the higher order natural frequencies,the total vibration and the vibration acceleration,and increase the composite loss factor of the pavement constrained damping structure.When the thickness of damping layer is more than 2mm,the thickness of damping layer is not very significant to the optimization of pavement constrained damping structure.In conclusion,the damping effect of the damping layer of asphalt pavement constrained damping structure is the best when 2mm is taken in the experimental range.Finally,according to the conventional performance and damping performance of Qtech-T502 viscoelastic damping material and the situation of construction site,the construction technology of vibration damping pavement is formulated and applied to the damping pavement of a viaduct in Qingdao.This paper mainly expounds the basic material treatment technology of concrete base,emphatically discusses the spraying damping construction technology,and sums up the technical problems and solutions in the construction of vibration-damping pavement.This paper mainly expounds the basic material treatment technology of concrete base,emphatically discusses the spraying damping construction technology,and sums up the technical problems and solutions in the construction of vibration-damping pavement.Through the above experiments,the effects of wet and dry cycles and high and low temperature cycling on the mechanical properties of viscoelastic damping materials are discussed,and the influence of damping layer material and damping layer thickness on damping performance of pavement constrained damping structure is studied,and the construction technology of vibration damping pavement is formulated.This paper provides the relevant data for the application of pavement constrained damping structure in road damping.