Research On Viscoelastic Properties And Interface Failure Behavior Of Low Temperature Sealants And Fillers

Asphalt pavement cracks will reduce the flatness and local stiffness of the pavement structure.The continuous expansion of the cracks may lead to more serious diseases,which will not only destroy the integrity of the pavement structure but also shorten the service life of the pavement.conservation.Sealants and fillers are the most widely used joint filling material,and their material properties and stress characteristics play a key role in the maintenance effect of asphalt pavement.Aiming at the modification,self-healing,aging and rheological properties of the existing sealants and fillers,it can effectively improve the maintenance effect of joint filling.However,there are still problems such as weak interface adhesion and poor anti-cracking effect at low temperature.The research status of the viscoelastic properties and interface failure behavior of caulking glue is still insufficient.Based on the existing research,firstly,this paper optimizes the preparation process of the sealants and fillers,and uses the correlation analysis method to optimize the ratio.Secondly,the viscoelastic properties of the low-temperature sealants and fillers are characterized by various macro and micro experiments.The geometric dimensions of the point-bending beam specimens were established to reveal the failure process of interface cracks.Finally,the acoustic emission signal parameters were used to characterize the density of micro-cracks.It provides technical support for the engineering application of the low-temperature sealants and fillers.The main conclusions are as follows:(1)The microscopic test analysis shows that the main reaction of the low-temperature sealants and fillers compound is physical blending,and the compatibility is good.the results of dynamic modulus and viscoelastic properties show that SBS,rubber powder,extraction oil,stabilizer and tackifier are mixed.The increase of the amount will improve the high and lowtemperature performance and fatigue resistance of the sealants and fillers to a certain extent.(2)The experimental results of acoustic emission nondestructive testing technology show that the crack propagation is divided into three stages.In the first stage,the compressive stress grows in a step-like manner,the acoustic emission parameters suddenly increase,the micro-crack develops stably,and elastic-plastic deformation occurs.In the second stage,the acoustic emission signal increased sharply,the crack expanded rapidly,and the cumulative number of impacts rose sharply.In the third stage,the amplitude increased sharply and densely at the unloading point,the impact count rate dropped sharply,and the cumulative number of impacts did not increase anymore.(3)The morphology of the damaged interface shows that the cohesion failure of the sealants and fillers occurs at 0℃;the adhesion failure of the joint-filling interface occurs at10℃;and the sealants and fillers fail at-20℃.There is a certain correlation between the effect of crack filling and the roughness of the damaged interface.The interface is flat and the roughness is small,which is prone to low-temperature brittle cracking;the interface is uneven and rough,and the failure is a viscoelastic failure.In conclusion,through the monitoring results of the law of viscoelastic properties and the interface failure properties,the optimal blending amount can be determined as SBS 8%,waste tire rubber powder 14%,extraction oil 4%,softener 0%,stabilizer 18%,tackifier 7%.The research results show that the self-developed low-temperature sealants and fillers not only meets the requirements of the specification,but also can recycle waste and reduce maintenance costs,and has significant social benefits such as low carbon,sustainability and green.