Research On The Long Term Performance Of High Density Polyethylene Geogrid Reinforced Materials

Reinforced retaining wall is widely used in road supporting engineering,because it is low cost,simple process and beautiful appearance.As a high quality material which is commonly used in soil reinforcement,there are some problems that can not be ignored.For example,the intensity of the geogrid will be attenuated by the influence of the ultraviolet radiation in the natural environment,and the characteristic of creep will be shown under the action of external force.These problems will affect the reinforcement effect of the grid,thereby endangering the safety of the wall.This paper is discussing the long-term performance of reinforced concrete materials,and the relevant test research is carried out on the problem of aging and creep of the grid,and all of the data is taking from concrete projects.Firstly,the tensile strength test of high density polyethylene geogrid used in the project is carried out.The mechanical properties of the new type of geogrid were discussed by the indexes of tensile strength and elongation.Secondly,the natural aging test and accelerated aging test are carried out respectively,then the aging characteristics of the grid products can be analyzed by experiment.Thirdly,two test of correlation problems is discussed on the basis of this,and a reasonable aging strength prediction method is offered based on the reciprocity law.In addition,creep tests were carried out under different tension levels before and after aging,and the effect of creep characteristics and aging on creep behavior were analyzed by the test results.Finally,the existing constitutive model for creep constitutive model is used to fit the creep test results compares to the model parameters,and find out whether the model is reasonable and effective or not.The experiment results showed that the varieties of high density polyethylene geotechnical grille has high tensile strength and small deformation,at the same time,obvious tension platform appears in tension,and the residual strength of the platform affects the actual use.The aging phenomenon of high density polyethylene under ultraviolet radiation will lead to the decrease of tensile strength and elongation.Intensity attenuation under natural aging test can be simulated by the accelerated aging test,and then convert the calculated by the reciprocity law.The creep behavior of high density polyethylene with high density polyethylene at low tension level has two stages of deformation characteristics,It is shown as elastic deformation and stable creep deformation,while the creep behavior will be further intensified under the effect of ultraviolet aging,and the specific performance shows that both the ultimate creep and steady creep rate increase.The empirical creep model and the three parameter viscoelastic constitutive model can be used to reflect the creep behavior of the geogrid in the case of low tension level.Among power function,hyperbolic function,logarithmic function and other three types of empirical creep model,the power function model of creep model is better fitted to the precision of the creep test data of the geotechnical grid.Compared aging model parameters before and after the value,it can be found that aging effect on behalf of geogrid tensile modulus of the model parameters value decreased significantly and aging Houtu grille in the accuracy of the model is generally lower than that of unaged model accuracy.