Rutting Prediction Method In Asphalt Pavement Using Fiber Bragg Grating Sensing Technology

Permanent deformation (rutting) of HMA is one of the major structural failures of flexible pavements. Significant rutting may influence the functional performance and comfort of asphalt pavements, and endanger the security of running cars. The increased rutting also causes severe diseases of the pavement structure. So predicting the potential rutting level practically and reasonably is important in the design and management of the asphalt pavement. According to non-linear viscoelasticity rheology theory and monitoring informations from Fiber Bragg grating (FBG) sensors, a calculation method of rutting prediction in asphalt pavement using Fiber Bragg grating sensing technology is introduced in this paper. The content of paper mainly contain following aspects:Firstly, base on the general concept of viscoelastic mechanics and model theory, some basic elements and models in viscoelasticity rheology theory is presented. By the analysis of creep curve's character in asphalt mixture, make sure a typical deformation curve should consist of three stages, including decaying creep, stable creep and accelerated creep. Ulteriorly, a non-linear element which acutally is a cross-section viscous element is brought forward to build a 5-element viscoelasticity model, which is applicable for describing deformation's character of asphalt mixture.Secondly, in response to the non-linear 5-element viscoelastic model raised, a series of researches are carried out based on test results to further analysis of their functional properties. Through unxial repeated loading creep test, viscoelastic parameters which would be used for asphalt pavement rutting's analysis and calculation are obtained and analysed, and 5-element model's creep deformation character and flow performance are computed and validated, as a evaluate indexη_Nis brought forward to distinguish the differences of asphalt mixtures' deformation characteristic.Thirdly, aiming at some FBG sensors' practical problems which would met frequently in road engineering's application, inluding poor coordinated working, low livability and loading position, some methods including calibration test, process improvement and modular design are attempted to make FBG sensors suit for various diagusting condition in the process of road building and management. And a series of indoor test and field monitoring' results testify that the application of FBG sensor in road engineering has excellently reliable performance.Finally, non-linear viscoelasticity model theory and monitoring technology of FBG sensors are integrate into a systemic technique, which captures the effect parameters about peak strain, temperature, load time form FBG sensors and pavement strucure, weather, traffic volume from othor way. All these informations will contribute to a calculation and analysis method of rutting prediction in asphalt pavement. In the end, accelerated loading facility (ALF) is used to validate the effect of calculation results of this rutting prediction method. The final results show that it is completely feasible to predict and calculate the rutting deformation in asphalt pavement using Fiber Bragg grating sensing technology.In this paper, some research about monitoring and analyzing process of asphalt pavement and FBG application technology, will do good for promoting the development of FBG technology in road engineering, accelerate scientific research methods and tools updating in engineering fields, and supply sufficient data and technical supports for rutting theoretical investigation and analysis of asphalt pavement.