| In order to ensure the safety and comfort of mountain tourist highway,this paper bases on the Chongqing traffic science and technology project-"Research and demonstration of key technology about service quality of wulong fairy mountain tourist highway",analyses the characteristic of the mountain tourist highway and researches the application of thin rubber asphalt overlay technology in the maintenance of the mountain tourist highway.Firstly,the highway characteristic and the asphalt pavement of Wu-Xian highway have been investigated,the maintenance technology of pavement have been analysed with the "safe&comfortable,green road" principle.Secondly,in order to ensure the skid resistance and the water stability of the mountain tourist highway,the pavement performance of the thin rubber asphalt mixture have been studied based on the binder properties,aggregate properties and aggregate gradation.Then,the stress of the asphalt pavement has been simulated by the Ansys,and the interlayer shear level of the mountain tourist highway has been divided,the thermal bonding method heating the pavement to 140 ??160? and paving the surface has been put forward,the interlayer shear strength has been measured by direct shear test.Finally,the energy consumption and carbon emission has been analyzed by LCA,the use of the crumb rubber has been calculated,the main results are:(1)The rainfall is rich of the Wu-Xian highway,sharp turn and steep slope are widely distributed,private car and tour bus account for 84.9%and 9.9%respectively;The strength grade of pavement are the "best",the pavement structure bearing capacity can meet the requirements,but the section of PCI rating for the "middle" and "second"accounts for more than half,the skid resistance and water stability of pavement decreases significantly,the Wu-Xian highway needs the medium maintenance;and the applicability of thin rubber asphalt overlay technology has been clarified.(2)In order to ensure the technical requirement of overlay mixture,the SBS-rubber asphalt is been choosed,the aggregate should be the basalt with bigger crushing value and abrasion value;two grading curve have been get by adjusting the through rate of 9.5mm?4.75mm?0.36mm?0.075mm with the SAC design concept;compared with the SMA10,the ARSAC10-I rubber asphalt mixture has better skid resistance,water stability,high and low temperature performance,it can meet the performance demands of the mountain tourist highway.(3)The interlayer shear grade I is 0.75MPa ??0<0.85MPa,grade ? is 0.85MPa??0<1.0MPa,grade ? is 1.0MPa ??0<1.2MPa;The shear strength of thermal bonding method is about 40%higher than that of the tack coat bonding,the shear strength of rubber asphalt overlay is about 40%higher than that of SBS asphalt overlay,the shear strength of rubber asphalt overlay with thermal bonding is 1.34MPa.(4)The energy consumption of material production stage and pavement construction account for 82.3%and 17.7%respectively,the carbon emission account for 80.0%and 20.0%respectively;in the whole overlay construction period,the energy consumption of thermal bonding is 1.11 times that of the tack coat bonding,and the carbon is the same as that of the latter one by 1.13 times;Under the condition of thermal bonding,the construction period of rubber asphalt overlay is 15.8%less than that of SBS asphalt overlay,and the emission reduction is about 4.6%,the energy consumption of Wu-Xian highway thin rubber asphalt overlay engineering is 7.7×106MJ,which is 1.4×106MJ less than that of SBS asphalt overlay,the carbon emission of former is 505.76t,which is 24.19t less than that latter.The consumption of crumb rubber in thin rubber asphalt overlay of Wu-Xian highway is 100.6t,it is equivalent to 17964 old car tyres;it can be seen that the thin rubber asphalt overlay technology has an evident environmental benefit. |
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