Research On Asphalt Pavement With Geogrid Reinforcement

Rutting is a major distress form found in asphalt pavements. Rutting is caused by the accumulation of irreversible (or permanent) deformation in all pavement layers under the action of repeated traffic loading. Among the contributions of rut depth by the various pavement layers, the cumulative permanent deformation in the surface course of asphalt pavement is well known to be responsible for a major portion of the final rut depth measured on the pavement surface. Therefor rutting resistance of a paving asphalt mixture is one of the important considerations in standard procedures for asphalt mix design.This paper reexamines potential usefulness of the Mohr-Columb concept for developing a rutting prediction model with geogrid reinforcement.(1) Past research has shown that the concept of Mohr-Columb concept can be applied for asphalt paving mix design. It has also been established that the Mohr-Columb concept is able to analyze the behavior of asphalt pavement with geogrid reinforcement by finite element analysis.(2) Immersion wheel tracking test for asphalt pavement with geogrid reinforcement is conducted in this study. This test was conducted to produce rut depth development data covering the parameters like the thickness of asphalt pavement surfacing, tension strength of geogrid and the placement of geogrid in the asphalt surfacing layer.(3) Many researchers abserved that rutting occurred as a combination of densification (volume change) as well as shear deformation (without volume change) , and the shear deformation rather than densification is the primary rutting mechanism. The model coefficients of the proposed rut depth prediction model based on power equation form include magnitude of traffic loads, loading speed, number of load repetitions, pavement temperature, and rutting resistance of asphalt mixture. They were determined by performing statistical regression analysis on the data derived experimentally and analytically from the rut depth development data in wheel tracking test and bearing capacity determined by finite element analysis.(4) The performance of pavement is the ultilty standard of pavement design, performance parameters of asphalt pavement is characterized by the inherent variability. It provides reference for evaluation of pavement perforcement,the design method of pavement based on pavement perforcement,and reliability of asphalt pavement with geogrid reinforcement. Thus, the approach for the statistic of the performance parameters in an asphalt pavement with geogrid reinforcement is illustrated in this study based on Monte Carlo simulation.(5) The structure composition for an asphalt pavement with geogrid reinforcement is analyzed and optimized by finite element method. It illustrates that the resistant of rutting in asphalt pavement is hightly increased by geogrid. The design for an asphalt pavement with geogrid reinforcement is proposed for the design method for specifications for design of highway asphalt pavement.