Experimental Characteristics Of Heat Conduction Of Asphalt Layers Mixtures

In order to realize the asphalt pavement’s thermodynamic characteristics, needed to understand the temperature field through the thermal conduction of asphalt pavement.The thesis based on Fourier’s heat conduction principle of independent research and development of the double test flat type heat conduction testing device, combined with the real pavement structure, the heat conduction experiment was carried out on the highway common asphalt mixture.The research according to the practical engineering, firstly pavement structure, select the AC-13 and AC-20 asphalt mixture, followed by consideration of mixture structure type and the present condition of engineering application, and select the SMA-13 and OGFC-13 asphalt mixture, after mix design and Road performance making the standard rutting specimen. Set the nine test temperature in-10~60℃, analyzed heat conduction performance of asphalt pavement through heat conduction test. According to the measured temperature of semi-rigid base asphalt pavement, the law of pavement temperature variation is analyzed, and the effect of thermal conductivity on temperature field is analyzed by finite element software.The results show that : The key factor that affects the thermal conductivity of asphalt pavement materials is the gradation type, the particle size and the temperature, and the amount of asphalt and the influence of the variety is weak. The thermal conductivity of asphalt mixture is a value of temperature change with increasing temperature increase linearly; dense graded mixture of thermal conductivity values are significantly higher than that of gradation type; coarse grain type mixture thermal conductivity values greater than fine style; Asphalt surface layer of material coefficient of thermal conductivity in the experimental temperature range value between 0.70~2.10W·(m·K)-1; the pavement temperature changes mainly diurnal variation, the asphalt surface layer changes strongly, weak base, subbase remained constant and the gradation type is first; asphalt pavement on the heat conduction process is usually transient and non-steady state. When in high temperature and low temperature, pavement temperature field has the same distribution in theory, but the value is different, distribution curve to the opposite and symmetrical. In high temperature transient strong and in low temperature even more tends to a steady state; thermal conductivity changes of temperature field has certain influence.