Research On Thermal Conductivity And Microwave Heating Performance Of Asphalt Concrete Containing SiC Aggregate

In order to popularize microwave heating road maintenance technology,It is the key issue to improve the microwave heating efficiency and heating uniformity of asphalt concrete while ensuring good road performance.This research attempts to solve the problem by using SiC abrasives as aggregates.Firstly,the electromagnetic parameters of SiC particles were measured by coaxial method and SiC microwave absorption properties were evaluated.Secondly,for reducing the heat transfer hysteresis and improving the heating uniformity,the effect of SiC on the thermal conductivity of asphalt concrete was investigated.Thirdly,the microwave heating efficiency,energy utilization rate,microwave durability and deicing performance of SiC aggregate asphalt concrete were studied by microwave heating test and the heating uniformity was also quantitatively evaluated.Finally,the road performance of SiC aggregate asphalt concrete was explored through laboratory experiments.The following main conclusions are drawn from the research:(1)The thermal conductivity of asphalt concrete increases significantly with the increase of SiC aggregate substitution.The highest thermal conductivity is 3.236W/(m K),which is 1.53 times that of ordinary asphalt concrete.(2)SiC aggregates significantly improve the microwave heating performance of asphalt concrete.The maximum microwave heating temperature rise rate of SiC aggregate asphalt concrete is 0.536℃/s,which is 2.63 times that of ordinary asphalt concrete.The energy utilization rate is increased to 55.97%,which is 2.23 times that of ordinary asphalt concrete.(3)After using SiC aggregate,the uniformity of microwave heating of asphalt concrete is obviously improved and the maximum standard deviation of surface temperature after microwave heating for 180 s is only21.25℃.In addition,the deicing performance has also been improved.Only using SiC aggregate,which accounts for 8.75% of the total aggregate mass,can shorten the deicing time at-10 °C to 42.2% of that of ordinary asphalt concrete.(4)SiC aggregate asphalt concrete has good road performance.In the best case,compared with ordinary asphalt concrete,the residual stability is increased by 10.1%,the dynamic stability is increased by 59.2%,the low temperature splitting strength is increased by 22.7%,and the BPN value is increased by 9.1%.This thesis contains 41 figures,11 tables,and 80 references.