Research On Creep Properties Of Embankment Dam Asphaltic Concrete Core Matertial

Asphalt concrete core material as the embankment dam seepage control system is widely used in the worldwide,asphalt concrete core dam became one of the important type of dams.Both heap of stone and asphalt concrete are creeping materials,after the completion of water of the dam,the dam and asphalt concrete core will produce creep deformation,creep deformation will caused the redistribution of internal stress and strain of asphalt concrete core,and even the destruction of the core.So it is necessary to carry out the creep properties research of hydraulic asphalt concrete core material.In this paper,on the basis of extensive reading of related research materials,combined with the related deficiencies in the study of hydraulic asphalt concrete creep,According to the project mixture ratio design plan,the research route of this article is determined : the hydraulic asphalt concrete are loaded with hierarchical and staged load creep test research.In consideration of the hydraulic asphalt concrete material porosity generally less than 3%,its volume creep deformation is small,so this paper only studies the law of the shear creep.The main research contents and results are as follows:1.The study of hydraulic asphalt concrete raw material properties and mixture ratio design research.Research showed that the main control design parameters of asphalt concrete mixture ratio are grading index r,the dosage of filler F and asphalt content B.The difference of r,F and B directly influence the basic properties of the asphalt concrete.2.The study of hydraulic asphalt concrete static triaxial tests.By means of which determines the failure strength parameters,provided the strength parameters for the next step of creep test.3.The study of hydraulic asphalt concrete creep test.Based on the fracture strength of the static triaxial test,conducted the creep test of hierarchical and staged load with stress level at 0.2,0.4,0.6,0.8 respectively.Using the Boltzmann linear superposition principle and the "Chen method" to process the graded loading test data.The results show that using hierarchical load to asphalt concrete creep test is reasonable and effective;For the hierarchical load creep test data,the "Chen method" is the optimum data processing method.4.Use the six parameters creep model of The Yangtze River Scientific Research Institute and the classic Burgers four parameters creep model to regression analysis of asphalt concrete creep test data.Regression analysis shows that: At the low stress levels,both of the two models can better to simulate the first stage of the creep curve.But with the increase of stress level,the two models are increasing the fitting error of the first stage of the creep curve.Regardless of the level of stress,both can better to simulation the second stage of the creep cueve.On the whole,the six parameters creep model of CRSRI has a small error,it's more suitable to simulate the characteristics of the three axial creep test of hydraulic asphalt concrete.