Experimental Study Of Low-Temperature Rubber Asphalt Stiffness Modulus

Low temperature cracking of asphalt concrete pavement, especially in coldregions, is one of the main forms of asphalt pavement. In northern China, the longcold winter, the laying of new asphalt pavement often in very short time after theopening of the road, there will be a regular distribution of transverse cracks. Aroundthe crack is the weak area of pavement damage, rainwater infiltration, can not betimely evacuation, intensified freezing up, freezing and thawing, causing asphaltpeeling, loose, potholes and other damage, resulting in pavement early damage of thepavement, the actual service life of large amplitude is lower than the design life.To solve the low temperature cracking of pavement damage, domestic andforeign scholars have done a lot of research. In twentieth Century50, Holland scholarVandel Poel proposed the concept of stiffness modulus, as a function of time andtemperature, can reflect the as a typical viscoelastic material of asphalt by therelationship between force and deformation, once it has been attached greatimportance to road engineering scholars.This paper studies the mechanism of modification of rubber asphalt, through theindoor test of rubber asphalt penetration, softening point, elastic recovery, adhesion ofbasic indicators, according to several basic index tests90#asphalt and rubber asphaltand its low temperature performance is analyzed.Secondly, through the study on the stiffness modulus definition, designed to threepoint bending test and low temperature asphalt mortar stiffness modulus. On theasphalt and mortar beam load, under different low temperature deformation dataanalysis, analyzed the deformation regularity of rubber asphalt mortar, strain andchange with time varying with temperature, and compared with90#asphalt andmortar. Based on the study of stress and deformation characteristics of asphalt and mortar on the low temperature, a variation of the research progress of rubber asphaltand mortar low-temperature stiffness modulus with time and temperature, ascompared with matrix asphalt and mortar for90#. In the test process are alsoconsidered factors of different dosage of rubber powder, loading time, temperature ofasphalt and mortar deformation and stiffness modulus. Shows the effect oftemperature on stiffness modulus is the key.Finally, the rubber asphalt mixture of different low temperature splitting test, thelow temperature performance of rubber asphalt mixture are evaluated, respectivelystudy the rubber asphalt mixture splitting strength, failure strain and failure stiffnessmodulus changes with temperature, and compared with the90#asphalt mixturematerial. At the same time, and the use of H-K method for stiffness modulus ofasphalt mixture stiffness modulus were compared to the experimental stiffnessmodulus of asphalt mixture at low temperature results, verify the validity of testmethods.