| The use of carbon fiber heating cables for road surface deicing and snow removal has become a hot research topic for scholars at home and abroad.However,there are relatively few reports on the impact of carbon fiber heating cables embedded in asphalt pavements on the mechanical properties of the pavement.To improve the mechanical performance of the asphalt pavement with carbon fibre heating cable,this thesis proposes to combine the heating cable with glass fiber grid,conduct semicircular bending tensile crack test on asphalt concrete with different structures,and establish a pavement structure model.In the two cases of heating,the rutting depth of the road surface is analyzed from different angles,an optimum combination scheme is put forward.The main work of this thesis is as follows:(1)Through the semicircle bending and pulling test and using digital image technology,the influence of carbon fiber heating cable-glass fiber grid composite structure on the crack resistance of asphalt concrete is analyzed,and a numerical model is established to discuss the situation of different layers of the grid.The results show that the carbon fiber heating cable reduces the crack resistance of asphalt concrete by about10%,while the addition of glass fiber grid improves the crack resistance of concrete.The grid structure of the glass fiber grid forms a mechanical interlock with the surrounding concrete,which effectively restrains Concrete deformation,with the increase of the number of glass fiber grid layers,the maximum bearing capacity of the structure gradually increases,and the stress concentration at the crack tip is improved more obviously.(2)Establish an asphalt pavement structure model to study pavement rutting under different working conditions at-5℃ ambient temperature.The results show that the addition of cables has a reinforcing effect on the pavement,and the rut depth is less than that of the non-cable concrete.With the increase of the distance between the cable and the buried depth,the rut depth will increase gradually.Considering the difficulty of construction and the overall pavement In the case of deformation,choose a working condition where the heating cable spacing is 150 mm and the burial depth is 5cm.Compared with the structure without reinforcement and only adding cables,the average vertical displacement of the road surface is reduced by about 29%,the maximum principal tensile stress is reduced by about 59%,and the maximum principal compressive stress is reduced by about 42% after adding fiberglass grating,the maximum shear stress is reduced by about 73%.When the road surface temperature is low,changing the driving speed has little effect on the rut depth on the road surface.(3)The heating of the carbon fiber heating cable is added to the pavement structure model,and the temperature distribution and rutting displacement of the pavement surface are analyzed from different angles.It is found that the shorter the distance of heating cable is,the shallower the buried depth is,the better the heating effect of the cables.Heated cable has a higher rut depth than unheated case.Along with the increase of the distance and the buried depth of the heating cable,the depth of the road is reduced gradually.Considering the complexity of construction,road surface temperature,and the influence of asphalt’s mechanical properties,heating cables are the most difficult to use.The optimum distance is 150 mm and the buried depth is 5 cm.Compared with the structure without reinforcement and only adding the cable,the vertical displacement value after adding glass fiber grating is reduced by about 30%,while the vertical displacement of asphalt concrete around the cable remains almost unchanged with the increase of temperature.The influence of heavy load on heated road surface is larger,but the influence of driving speed is small. |
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