Pavement performance prediction is a crucial issue in big data maintenance. This paper develops a hybrid grey relation analysis (GRA) and support vector machine regression (SVR) technique to predict pavement performance. The prediction model can solve the shortcomings of the traditional model including a single consideration factor, a short prediction period, and easy overfitting. GAR is employed in selecting the main factors affecting the performance of asphalt pavement. The SVR is performed to predict the performance. Finally, the data collected from the weather station installed on Guangyun Expressway were adopted to verify the validity of the GRA-SVR model. Meanwhile, the contrast with the grey model (GM (1, 1)), genetic algorithm optimization BP[[parms resize(1),pos(50,50),size(200,200),bgcol(156)]]081%, −0.823%, 1.270%, and −4.569%, respectively. The study concluded that the nonlinear and multivariate prediction model established by GRA-SVR has higher precision and operability, which can be used in long-period pavement performance prediction.

Five types of material, styrene-butadiene-styrene block copolymer (SBS), ethyl-vinyl-acetate (EVA), naphthenic oil, maleic anhydride grafted ethylene-vinyl acetate copolymer (EVA-g-MAH) and butylated hydroxytoluene (BHT) were used as the raw ingredients for manufacturing direct-to-plant SBS in this paper. Thirteen kinds of direct-to-plant SBS with different EVA/SBS and naphthenic oil/SBS were prepared as well as the processes diagrammatic sketch of dispersion and swelling of direct-to-plant SBS modifier in bitumen were discussed. Microscopic images of direct-to-plant SBS modified bitumen with different components were obtained using fluorescence microscopy. The micro-images were analysed and quantified with MATLAB software. The influence of key components on the micro-morphology of direct-to-plant SBS-modified bitumen is discussed, followed with the tests on melting points and the melting indexes of direct-to-plant SBS with different EVA/SBS and naphthenic oil/SBS. The performances test of bitumen and bituminous mixture modified by these direct-to-plant SBS were also conducted. Results show that, with the ratio improvement of EVA/SBS or naphthenic oil/SBS, the number of the pixel dot number of area (SBS) in microscopic images increased. Enlargement of the pixel dot number of centre line elongate and the structure fineness was observed, indicating that the dispersion and swelling effect of the SBS modifier in bitumen had been improved. Meanwhile, the macro index, such as the melting point and melting index of direct-to-plant SBS, was also improved corresponding to the increase of EVA/SBS ratio or naphthenic oil/SBS ratio. With the addition of EVA or naphthene oil content, penetration and ductility of direct-to-plant SBS modified bitumen received gradual enhancement, but the softening point and viscosity were found out to be decreased. The high-temperature and low-temperature performances of direct-to-plant SBS modified bituminous mixture can be effectively improved by adding EVA or naphthenic oil. By meeting the required performances of direct-to-plant SBS, modified bitumen and bituminous mixture, the component of direct-to-plant SBS is recommended as, SBS:EVA:naphthenic oil:EVA-g-MAH:BHT is 1:0.1–0.5:0.05–0.2:0.03:0.05. For the compatibleness of SBS with different bitumen are different, necessary tests verification is recommended to be carried out prior to usage.

A method of deicing using microwave heating is proposed to make scientific and economical road deicing in a cold area, and to make up for deficiencies in the existing methods for melting snow and ice. This paper proposes to define microwave deicing efficiency as the heating rate of a concrete surface when heated to 0 °C (the efficiency of deicing is equal to the difference divided by heating time, which is between 0 °C and the initial temperature at the junction of ice and concrete). Based on the mechanism of microwave heating and deicing, a method combining the finite element simulation model with indoor experiments was proposed to study the deicing efficiency of microwaves, and the effects of different microwave frequencies and different road structure materials on microwave deicing efficiency were analyzed. The results show that the microwave frequency and road structure materials have a great influence on microwave deicing. For asphalt concrete, the ice melting efficiency of 5.8 GHz is 4.31 times that of 2.45 GHz, but the heating depth is less than that of 2.45 GHz. At 2.45 GHz, the melting efficiency of cement concrete is 3.89 times that of asphalt concrete. At 5.8 GHz, the melting efficiency of cement concrete is 5.23 times that of asphalt concrete. Through the consistency of the simulation and experimental results, the validity of the simulation model based on the finite element theory is verified. The results provide theoretical guidance and a practical basis for future applications of microwave deicing.

In order to improve the problem of the bad thermal storage stability of Styrene-Butadiene-Styrene Block Copolymer Modified Bitumen (SBS-modified bitumen), the vulcanization reaction was selected as the basic mechanism for the research and development of the stabilizer. Sulfur, tetramethylthiuram disulfide (TMTD), zinc oxide, butylated hydroxytoluene (BHT), kaolin (Al 2 O 3 •2SiO 2 •2H 2 O) and carbon-white (SiO 2) were used as raw materials, and 32 kinds of components with different contents of raw materials were designed. The 48-h segregation softening point and other modified bitumen technical indicators, such as ductility, penetration, penetration index, viscosity, and so on, were tested and analyzed. The fluorescence microscope test was also conducted to explore the crosslinking situation based on the vulcanization reaction. The results show that the component with good performance of the SBS-modified bitumen stabilizer powder was S:TMTD:ZnO:BHT: Al 2 O 3 •2SiO 2

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At present, the geogrid is commonly used to treat the differential settlement of the subgrade at the joint of the filling and excavation effectively. In order to further improve the utilization rate of geogrid in the treatment of subgrade, the driving comfort index was proposed innovatively to control the subgrade differential settlement. Based on the human-vehicle-road coupling system model, the influence of subgrade differential settlement area, subsidence value, and vehicle speed on the maximum vertical acceleration of the human body was analyzed. The correlation between the vertical acceleration of the human body under different vehicle speeds and the differential settlement value was obtained through multiple regression calculations, and the subgrade differential settlement control standard based on driving comfort was proposed. By establishing the finite element model of the cut to fill subgrade, the characteristics of differential settlement at the top surface of the subgrade under different geogrid laying positions, densities, and lengths were calculated and analyzed. In addition, the differential settlement layout scheme of the geogrid disposal subgrade based on driving comfort was proposed, and the effectiveness of the scheme was verified by experiments. The results show that the position and length of the grid are the main factors affecting the treatment effect of the vertical and horizontal cut to fill subgrade. The proposed layout scheme can effectively control the differential settlement of the subgrade and raise the utilization rate of the geogrid. The research results can provide theoretical value and reference for the laying of geogrid in mountainous roads.

Thermo-oxidative ageing is one of the main factors affecting bitumen performance. At present, the research on bitumen ageing has entered the micro stage. The purpose of this paper was to study the relationship between nano-morphology parameters and properties of bitumen of bitumen during the ageing process. To this end, bitumen with different ageing degrees was prepared in this paper, and Atomic force microscopy samples with different cooling rates were prepared. The relationship between ageing degree of bitumen and nano-morphology parameters was analyzed. A functional relationship model between nano-morphology parameters and properties of bitumen was established. The results show that the percentage of bee-like structure area ( P bee − like ), maximum amplitude ( H max ) and roughness ( R q ) increased with the increase of ageing degree. the percentage of bee-like structure area, the maximum amplitude and the roughness increase with the increase of cooling rate. With the increase of the percentage of bee-like structure area, the maximum amplitude and the roughness, the viscosity of bitumen at 60 °C increases, penetration decreases, and softening point increases. There is a nonlinear relationship between the nano-morphology parameters and properties of bitumen.