Strength Characteristics Of Asphalt Mixture Based On Three-direction Independent Load Under Low Temperature And Application

The theory of maximum tensile stress, the maximum tensile strain or the Mohr-Coulomb theory had been commonly used to represent strength of asphalt mixture.The existing asphalt testing method, such as uniaxial compression test, bending test,direct tensile test, splitting test even conventional triaxial compression test, have beenup to the first principal stress and the third principal stress rational explanation ofasphalt mixture.Nevertheless, it is existed that the common denominator is the lack ofasphalt mixture intermediate principal stress effectresearch. The strength properties ofAC-13C and SUP-13mixture have been analyzed by the self-developed true-triaxialstrength tester of asphalt mixture,and it has been applied to the material strength andcracking anticipation of asphalt pavement.The true triaxial strength test of asphalt mixture was carried out under differentgradations, temperature conditions and binder. What’s more, the various factors thataffect the mechanical properties of asphalt mixture was analyzed.The existence ofintermediate principal stress effect was revealed and the common of AC-13C andSUP-13asphalt mixture intermediate principal stress effect was summarized.It isindicated that the effect of intermediate principal stress can not be ignored in strengthcharacteristics’ research. It is showed that the allowable stress value growthcoefficient is related to the gradation and binder of asphalt mixture. The limitmeridianfailure equation on the plane of under stress angle at60of AC-13C andSUP-13asphalt mixture was obtained by true-triaxial test under different pressureconditions. Combined with the natural environment of the alpine region of theKarakoram Highway, the cracking of asphalt pavement was anticipated based on thetrue-triaxial strength equation. Compared with Mohr-Coufomb strength theory, it isdemonstrated that using the true-triaxial strength equation of asphalt mixture todetermine whether there will be damage phenomena has been considered closer to thereal situation of asphalt pavement after the finite element analysis at low temperaturebending test results.