Research On Date Analysis Method Of Vibration Compaction Of Asphalt Pavement

Compaction is the key step of asphalt mixture forming and road function realization,which has a significant influence on the stability,strength and anti-fatigue performance of the pavement.At present,the compaction quality of asphalt pavement is still obtained mainly by spot check afterwards,which is not timely and representative.Therefore,the method of continuous detection of compaction quality in vibration compaction process of asphalt pavement is a research hotspot.Based on the comparison of mainstream analysis methods,this paper analyzes the application of selected methods and compaction control indexes in asphalt pavement through the simulation of dynamic model and finite element model.First of all,the relevant mechanism of vibration compaction process and the compaction characteristics of asphalt mixture are analyzed,and the indicators of the mainstream analysis methods are selected considering the engineering practicability.The results show that the plastic deformation is the main deformation mode of asphalt pavement compaction.Vibration acceleration indicators have advantages in signal extraction and calculation convenience,and vibration acceleration amplitude and harmonic ratio(CMV,CCV,RMV,THD)are selected for further research.Secondly,through the comparison of the simulation models of the compaction process,the improved two-degree-of-freedom vibration wheel and spring damping coupling model is selected to solve the dynamic formula and simulate.The results show that in the process of vibratory compaction,the vibration acceleration can reflect the resistance of the compacted asphalt pavement,and the tonnage,exciting force and exciting frequency of the roller will affect the correlation.It is an obvious theoretical correlation between the vibration acceleration amplitude and the compaction degree,and within the conventional compaction degree range of the compaction operation,the linear relationship between the two has a good fitting effect,and R~2 is 0.99.Then,the three-dimensional finite element simulation model of asphalt pavement vibratory compaction process is established and verified,and the influence law and sensitivity of vibratory roller parameters are studied.The results show that within a reasonable range of parameters,increasing the exciting force,tonnage,and exciting frequency of the road roller,and reducing the driving speed can improve the compaction efficiency,and the optimal excitation frequency varies with the compaction of pavement;The exciting force and tonnage are the key parameters to improve the compaction efficiency of asphalt pavement,and their sensitivity indexes are 0.405 and 0.312 respectively.The speed and exciting frequency have little influence,and their sensitivity indexes are 0.231 and 0.09 respectively;The optimized working parameters of the road roller are proposed.The method of heavy pressure and low speed in the initial stage,and light pressure and high speed in the later stage,has the best compaction effect.Finally,the selected harmonic ratio and amplitude indexes are compared by using the finite element model,and the prediction model of asphalt pavement compaction quality is established combined with the most suitable indexes and influencing factors.The results show that among the selected research indicators,CMV is more suitable for continuous detection of asphalt pavement compaction quality.The influence of the substructure layer on the correlation is relatively low,and the influence of temperature,roller excitation force and frequency is significant;The correlation coefficient of the prediction model considering significant influencing factors is 0.7654,and the sampling results show that the relative error of the prediction model is within 2%,which meets the specification requirements.