Research On The Cooling Shrinkage Cracking Characteristic Of Asphalt Mixture

Low-temperature shrinkage cracking is one of the main damage forms in highway asphalt pavement. This damage seriously affected on the normal use of asphalt pavement. On the basis of existing researches, this paper researches the cooling shrinkage cracking characteristics of asphalt mixture, in order to increase the anti-low temperature cracking capacity of asphalt mixture, and provide the foundations for asphalt mixture designing.On the basis of analyzing the test methods and evaluation indicators of the thermal stress restrained specimen test of asphalt mixture, this paper develops tester of asphalt mixture cooling shrinkage cracking, proposes the test methods and evaluation indicators of cooling shrinkage cracking. Through the cooling shrinkage cracking tests of asphalt mixture, the author analyzes the asphalt grade, asphalt dosage, aggregate type, particle size, mineral gradation, cooling rate and the initial temperature and so on, which impact on asphalt mixture cooling shrinkage cracking. The conclusions are that, we can improve the anti-low temperature capacity of asphalt mixture though using the high-grade modified asphalt, making the mixture in the best asphalt dosages, selecting the aggregate in excellent performance, increasing the maximum size of the mixture and designing good gradation rate. In addition, we can reduce the cracking rate of asphalt pavement by slowing the cooling rate or improving the initial temperature.