Research On Asphalt Mixture Performance Based On Measured Response Of Embedded Strain Sensor

In recent years,China’s freeway has been developing rapidly.The asphalt pavement structure appears premature diseases such as fatigue cracking and rutting deformation with the continuous increase of car ownership,axle load aggravation and the formation of channelized traffic.The application of intelligent sensing technology to asphalt mixture pavement structure can provide support for the long-term service performance of pavement by monitoring the change trend of pavement structure performance.Based on the indoor loading test and finite element simulation analysis of asphalt mixture with strain sensor,the creep performance,fatigue performance and internal deformation characteristics of asphalt mixture structure were studied.Firstly,four-point bending loading tests of asphalt mixture beams with strain sensors were carried out in this paper,the effectiveness of the measured response of the embedded strain sensor was verified by establishing the correction relationship between the calculated strain and the measured strain.The finite element model of the coordinated deformation between the embedded strain sensor and the asphalt mixture was established,and the coordinated deformation coefficient was proposed to characterize the coordinated deformation performance between the embedded strain sensor and the asphalt mixture,the results shown that the embedded height of the strain sensor has little influence on the coordinated deformation between the embedded strain sensor and asphalt mixture,and the coordinated deformation between the embedded strain sensor and asphalt mixture decreased with the increase of the modulus of the strain sensor.Secondly,four-point bending creep and fatigue tests of asphalt mixture beams with strain sensors were carried out to study the creep and fatigue damage accumulation process of asphalt mixture.Based on the fatigue test results,the semi logarithmic fatigue equations of flow times FN and fatigue life were fitted respectively.The results shown that the semi logarithmic fatigue equation established by the flow times can not only reflect the fatigue characteristics of asphalt mixture,but also had lower sensitivity to the stress level.The fatigue performance of asphalt mixture was evaluated by the relative residual fatigue life ratio T.Finally,the rutting test of double-layer rutting plate with strain sensor was designed,and the development law of the internal flow deformation of double-layer rutting plate was studied.The results shown that under the condition of rutting test,the material at the position of the sensor was in the tension state in the transverse direction,and with the effect of high temperature wheel load,the lateral flow occurs continuously and the cumulative deformation occurs;The material at the sensor position of the specimen was in the state of alternating compression and tension in the longitudinal direction,and the longitudinal flow amplitude gradually decreases with the effect of high temperature wheel load.This paper studed the internal strain response of asphalt mixture measured by embedded strain sensor under external load,which could provide reference for the application of embedded sensor in actual pavement.