| Porous asphalt pavement,one of the“green”pavements with the most environmental protection concept,can not only alleviate the urban waterlogging caused by rapid rainfall,but effectively reduce the noise problem caused by the increasing number of vehicles.However,this kind of"green"pavement,which is safe,environmentally friendly,and comfortable,is mostly used in the eastern rainy areas.With the development of the road network and economy,the roads and vehicles in the southwestern region have shown rapid development,which brings more and more serious noise and environmental problems.Therefore,it is of great significance to use porous asphalt pavement in the western region.In view of this,this paper will carry out research on PAC road materials and properties in plateau areas from the following aspects:Orthogonal tests with rutting factor,fatigue factor,Brinell’s viscosity,creep rate and creep stiffness as response values by Box-Behnken design in response surfaces with elastomer,viscosity enhancer and compatibilizer admixture as variables;The optimal high-viscosity asphalt ratio was optimized by optimizing the response values and response output values;The low-temperature properties of three high-viscosity asphalts in the origin,TFOT and PAV states were comprehensively analyzed;Exploring the degree of correlation of different low-temperature evaluation indexes by the gray correlation entropy analysis with creep rate as the reference series;The fatigue resistance,rutting resistance,temperature sensitivity and aging resistance of the three high-viscosity asphalts were investigated by using the S-VECD model of LAS,multiple stress creep recovery,temperature scanning and frequency scanning tests;The microscopic analysis of high-viscosity asphalt was carried out using Fourier infrared spectroscopy.The results show that HVA has better high and low temperature performance compared to HVA-1 and HVA-2;The gray entropy correlation of m_r(60)low-temperature evaluation index is the highest,followed by the residual stress percentage index at 1 s.The difference in fatigue life of the three high-viscosity asphalts is not obvious in the short-term aging condition,and the fatigue life of HVA is significantly better than the other two as the aging degree increases;HVA and HVA-1 are less temperature sensitive and have better anti-aging properties than HVA-2.The effects of different gradations,void ratios,and nominal particle sizes on the noise reduction performance of porous asphalt mixtures were investigated comparatively after freezing without water immersion and after freezing with water immersion.The results showed that the absorption coefficients of the porous asphalt mixes were reduced after water immersion,and the sound absorption properties showed different variation patterns affected by the void ratio,gradation,and nominal particle size.The changes of high and low temperature,water stability,crack expansion performance,and dynamic modulus mechanical properties of different types of porous asphalt mixtures were studied by rutting test,low temperature bending beam test,water immersion Marshall test,freeze-thaw test,semicircular bending test,and dynamic modulus test.The results show that the porous asphalt mixture with a nominal particle size of 13.2 mm has the best high-temperature performance;Under the same grading conditions,the low-temperature performance of porous asphalt mixture is HVA>HVA-1>HVA-2 in descending order;The trend of decreasing water stability with increasing nominal particle size as well as void fraction;The dynamic modulus and phase angle are mainly affected by temperature and loading frequency,and the main curve of dynamic modulus shows an"S"shape and the main curve of phase angle shows a"bell"shape. |
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