关键词: 沥青混凝土, 大变形, 三轴试验, 蠕变速率, 蠕变加速度

Abstract: To study the creep characteristics of asphalt concrete after large deformation, triaxial tests are conducted under the conditions of four different temperatures and three different confining pressures, and creep tests are made under the axial stress corresponding to a deviating stress at the axial strain of 20%. The results show that the creep curves are quite different from those of regular creep tests, and the temperature and pressure impose varying effects on creep strain. At initial test stage, the influence of these factors is relatively weak, while with time passing in later stages, creep strain increases with test temperature significantly, but decreases with confining pressure to a certain extent. Under variations in both factors, variation patterns in creep rate and creep acceleration show that very close turning points occur in the sample￠s creeping; The average creep rate at these turning points can be used as a threshold of the turning for the creep stage of asphalt concrete after large deformation. The time to reach the turning point depends on the factors, as shown by our analysis. The higher the temperature or the smaller the pressure, the faster the turning point of creeping will be reached.

Key words: asphalt concrete, large deformation, triaxial test, creep rate, creep acceleration