Study On Road Performance And Thermal Insulation Performance Of Thermal Resistance Epoxy Asphalt Mixture

In order to solve the problem of roads in permafrost regions,this paper uses thermal resistance aggregates as a mixture aggregates to reduce the thermal conductivity of the pavement and prevent heat from being transferred to the subgrade to reduce the temperature inside the pavement.However,due to the limitation of the conventional thermal resistance asphalt mixture in road performance and thermal resistance.In this paper,the thermosetting epoxy asphalt material will be used to replace the conventional thermoplastic asphalt material,and the properties of the thermal resistance epoxy asphalt mixture are studied.First,this paper selects ceramsite aggregate as thermal resistance aggregate,and carries out research on volume parameters,high temperature performance,low temperature performance and water loss resistance of epoxy asphalt mixture with ceramsite,and selects SBS modified asphalt mixture for Comparison.Second,the influence of different compaction work on the gradation change and road performance of ceramsite epoxy asphalt mixture are investigated.Third,the indoor equivalent heat radiation test and thermal property test are selected to evaluate the thermal resistance of ceramsite epoxy asphalt mixture the ceramsite epoxy asphalt mixture.Finally,the numerical simulation of the thermal resistance epoxy asphalt insulation layer structure is carried out to verify the effectiveness of the thermal resistance performance.The main findings are as follows:(1)With the increase of the proportion of ceramsite incorporation,the dynamic stability,residual stability and TSR of epoxy asphalt mixture are gradually reduced.The bending strength and bending strain of epoxy asphalt mixture are also reduced due to the incorporation of ceramsite,but still meeting the requirements of the specification.However,the road performance of thermoplastic SBS modified asphalt mixture showed a downward trend,and Marshall Stability and dynamic stability can not meet the specification when the maximum dosage was 63%.(2)As the number of times of compaction increases,the gradation of the mixture shows a trend of reduction of coarse aggregate and increase of fine aggregate;from the perspective of road performance,with the increase of the proportion of ceramsite incorporation The dynamic stability of the ceramsite epoxy asphalt mixture(hereinafter referred to as EA-50)under the 50 compaction process is higher than the ceramsite epoxy asphalt mixture(hereinafter referred to as EA-75)under the 75 compaction process.The water stability and low temperature performance of EA-50 were not much different from those of EA-75.(3)For the indoor equivalent thermal radiation test,the temperature of the upper surface of the test piece increases with the increase of the ceramsite content under the same illumination intensity and illumination time,and the temperature of the bottom surface of the test piece decreases with the increase of the ceramsite content.That means the temperature difference between the upper and bottom surface increased with the increase of the ceramsite aggregate content.This result indicated that the ceramsite epoxy asphalt mixture can significantly reduce the heat transfer into the surface layer.For the thermal property parameter test,as the ceramsite aggregate content increases,the thermal conductivity and thermal diffusivity of the ceramsite epoxy asphalt mixture gradually decrease,while the heat capacity increased.However,the higher the amount of the ceramsite epoxy asphalt mixture,the decrease in thermal conductivity and thermal diffusivity and the increase in heat capacity were significantly slowed down.(4)By establishing a finite element model of thermal insulation epoxy asphalt insulation layer structure,the calculation results show that,for the temperature of the top of the roadbed,compared with the conventional structure,the average daily temperature of the insulation layer structure decreased by 3.88 °C in summer,while the average daily temperature in winter decreased by 1.42 °C,and the annual difference was reduced by 2.46 °C.For the road surface temperature,the temperature of the insulation layer structure is higher than that of the conventional structure at noon,and the highest road surface temperature difference is 4.6 ?.For heat flux density,the heat flux density of the insulation layer is reduced by 45.6%(2cm)and 68.4%(9cm)in summer,while the heat flux density in winter was reduced by 49.2%(2cm)and 68.4%(9cm).This results demonstrated that the epoxy asphalt insulation layer structure can effectively reduce the heat into the pavement structure and reduce the heat flow density.Thus,the epoxy asphalt insulation structure can protect the thermal stability of the frozen soil.