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To study the effects of steel slag on the skid resistance and durability of asphalt mixture, the effects of steel slag blending ratio and aggregate type on the anti-skid durability were analyzed. Next, the anti-skid durability of steel slag asphalt mixtures with different blending composition was comprehensively evaluated with index IFI. In addition, the mechanism of anti-skid durability was investigated through combination of atomic force microscopy (AFM) and X-ray diffraction (XRD) tests. The results show that with the increase of steel slag dosage, final steady-state value of the pendulum increases, while that of the texture depth reaches the maximum when the steel slag dosage amount is 75%. The combination of 75% steel slag + 25% basalt / limestone is recommended. the more angular morphology of the steel slag and its harder mineral component than basalt and limestone exhibit their diversity polishing values under repeated loading, thereby delaying the attenuation of the anti-skid performance of the asphalt mixture. [ABSTRACT FROM AUTHOR]

Considering the characteristics of steel slag, the effective relative density of steel slag was measured by the impregnation method. By the volume substitution method, the asphalt mixtures with different steel slag content were prepared for replacing the coarse aggregates. According to the technical requirements of the ultra-thin friction course, the road performance and the function characteristics of the steel slag asphalt mixture were evaluated. The test results show that with the increasing of steel slag content, the performance indexes of dynamic stability, maximum tensile strain and tensile strength ratio of asphalt mixture are increased with latter decreasing. When the steel slag content is 50%, the comprehensive performance of asphalt mixture is the best. With the increasing of the placement time of test specimens, the high temperature performance index of the steel slag asphalt mixture is increased slightly, while the low temperature crack resistance index and water stability index are decreased. The skid resistance and abrasion resistance of asphalt mixture are significantly improved with the addition of steel slag. The impermeability of the mixture is reduced, while the water seepage coefficient values of several steel slag asphalt mixtures can still meet the requirements of the standard test methods of bitumen and bituminous mixtures for highway engineering (JTG E20—2011). [ABSTRACT FROM AUTHOR]

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To evaluate the effectiveness of different types of warm-mixed agents and recommend the applicable areas, the warm-mixed agents with different viscosity reduction mechanisms of PRLT, Sasobit, Aspha-min and HH-XII were selected. SGC rotary compaction test, thermodynamic analysis and pavement performance test were carried out, and the effects of the types of warm-mixed agents on cooling effect, energy consumption and pavement performance of the asphalt mixture were investigated. The efficiencies of four warm-mixed agents were evaluated based on grey correlation theory. The results show that the mixing and compaction temperatures of SBS modified asphalt mixture can be reduced by four warm-mixed agents with different viscosity reduction mechanisms, and the best cooling effect can be obtained by PRLT with greatly reduced energy consumption. The high temperature performance can be improved by Sasobit, and Sasobit can be used in high temperature and heavy load areas. The low temperature and water stability performance can be improved by PRLT, but PRLT has adverse effects on high temperature performance, so it is suitable for asphalt pavement construction in seasonal freezing areas. Aspha-min asphalt mixture has the best low temperature performance and can be used in severe cold areas. HH-XII has negative effect on the high and low temperature performance of asphalt mixture, while the water stability can be improved by HH-XII, and HH-XII can be used in areas with heavy rainfall. PRLT has the greatest correlation with the performance of warm mix mixture, and it has the best overall performance. [ABSTRACT FROM AUTHOR]

The effects of ambient temperature, driving load and driving speed on the permanent deformation of asphalt pavement were explored. The grey correlation method was used to determine the significance level of the influence of multiple factors of continuous temperature change conditions, pavement material deformation characteristics and construction quality on rutting deformation. According to the principle of equivalent rutting deformation, the equivalent temperature numerical simulation analysis was carried out, and the rutting deformation-temperature relationship model was obtained to determine the equivalent temperature of rutting deformation in different months. A finite element analysis method of long-term permanent deformation of asphalt pavement was established based on ABAQUS, which was used to analyze the variation law of actual rutting deformation of asphalt pavement with service time. The results show that the environmental temperature, the driving load and the driving speed all have great influence on the rutting deformation of asphalt pavement, and the decreasing influence sequence is the environmental temperature, the driving load and the driving speed. The numerical simulation analysis of equivalent temperature shows that the monthly equivalent temperature of rutting can effectively characterize the rutting deformation of the pavement. The established prediction model can effectively predict the permanent deformation of the asphalt pavement, which can provide reference for controlling the construction quality of the asphalt pavement and guiding the later maintenance of the pavement. [ABSTRACT FROM AUTHOR]

A new type of low temperature cold patch asphalt liquid was developed by using waterborne epoxy resin and SBR latex to modify the solvent cold patch asphalt liquid. The dispersibility of waterborne epoxy resin and SBR latex in diluted asphalt was studied. Based on the orthogonal test, the composition of low temperature cold patch asphalt was recommended with viscosity at 60 ℃, mass loss rate at 3 d, viscosity difference before and after cold patch asphalt replenishment storage, softening point and flexibility of distillation residue as indicators. The performance of the waterborne epoxy resin-SBR cold patch asphalt mixture was evaluated. The results show that water-borne epoxy resin and SBR latex have good micro-disperse performance in diluted asphalt.The composition and dosage of waterborne epoxy resin-SBR cold patch asphalt are determined with matrix asphalt SK90# and with the amounts of diluent, tackifier, anti-spalling agent，water-borne epoxy component and SBR latex agent of respective 26.0%, 5.0%, 0.5%, 4.0% and 2.0%. The forming Marshall stability, dynamic stability and bending tensile strength of self-developed cold patch asphalt mixture are respective 74%, 91% and 26% higher than those of ordinary cold patch asphalt mixture, and the residual stability is 89%. [ABSTRACT FROM AUTHOR]

To improve the high temperature stability of asphalt pavement and alleviate the urban heat island effect, a color reflective asphalt pavement coating was developed. The amount of raw materials and the preparation process of coating were determined, and the cooling effects of color coating were tested and analyzed. The effect of coating on the surface function of pavement was tested, and the improvement measures were put forward. The results show that the cooling effect is the best when the volume ratio of TiO2 to film forming base is 2.8%. The cooling effect of the coating is improved with the increasing of color filler, while the cooling effect tends to be unchanged when the color filler is larger than a certain threshold. The volume ratios of color filler to film forming base are recommended from the economic and cooling effect with red of 2.7%, green of 2.6% and yellow of 3.2%. In order to improve the anti-slide performance and abrasion resistance of the coating, 0.48~0.50 kg·m-2 mechanical sand should be sprayed in the middle part of coating, and the light calcium carbonate with 30% coating quality should be added. [ABSTRACT FROM AUTHOR]

To deeply investigate the pavement performance of cold patch asphalt liquid and make up the deficiency of evaluation method, the performance evaluation method of cold patch asphalt liquid was put forward. A new type of solvent cold patch asphalt liquid was developed by orthogonal experiment, and the suggesting technical requirements were proposed. The properties were validated by comparison experiment. The results show that diluent and tackifier are the main affecting factors on the performance of solvent cold patch asphalt liquid. The optimum ratio of base asphalt, diluent, tackifier, surfactant and anti-stripping agent of the new type of solvent cold patch asphalt liquid is 100 ∶25 ∶2 ∶0.5 ∶0.6. The evaluation methods and the suggesting technical requirements of cold patch asphalt liquid can well reflect the pavement performance. According to the suggesting technical requirements, the excellent cold patch asphalt mixture can be prepared by the cold patch asphalt liquid. [ABSTRACT FROM AUTHOR]