Asphalt Mixing In Uniaxial Compression Mode Study On Influencing Factors Of Dynamic Modulus

Modulus of pavement materials is the basic parameter in pavement design.With the development of pavement design theory,the dynamic modulus is widely introduced into the asphalt pavement design method because it can effectively reflect the stiffness characteristics of asphalt mixture with temperature and load time.In view of the advantages of dynamic modulus and practical significance,this paper has carried on the research of dynamic modulus test of asphalt mixture under the uniaxial compression test mode,which is based on the full road test circuit of the Highway Science Research Institute of Ministry of Transport.On the basis of fully investigating the latest research progress of dynamic modulus at home and abroad,the concept of viscoelasticity,dynamic modulus,time-temperature superstition and main curve of asphalt mixture are expounded,and the dynamic modulus indoor test method is carried out.Introduction.The dynamic modulus test of 9 types of asphalt mixture in asphalt pavement of test loop was carried out by using UTM multifunctional material experiment system.Several factors affecting the dynamic modulus are studied,including temperature,frequency,asphalt material,gradation,porosity and so on.In order to study the effect of porosity on the dynamic modulus of asphalt mixture,three kinds of piles with different voids were molded and analyzed by using different compaction times.The results showed that the asphalt mixture The dynamic modulus decreases with increasing porosity.The main curves of the dynamic modulus and the main curve of the phase angle are studied.The displacement factor is obtained by the least squares method.The modulus curve measured at each test temperature is translated to the reference temperature,and the dynamic modulus main curve and the Sigmoidal model are constructed.The phase angle curve and the GuassAmp model are constructed by translating the phase angle curve according to the displacement factor of the dynamic modulus main curve.The Hirsch modulus maxima estimation model combined with the Arrhenius shift factor calculation model was used to establish the dynamic modulus principal curve and compared with the method of direct translation of the shift factor by the least squares method.The static modulus test of the same batch of molded specimens was carried out by UTM experiment system,and the influence factors of static modulus of asphalt mixture were discussed.According to the dynamic modulus and static modulus test results,the difference between the two tests is compared and analyzed.The transition between dynamic and static modes is established by linear programming in order to obtain dynamic modulus from simple test equipment.