In seasonally frozen regions, concrete pavement is exposed to cycles of freeze-thaw and erosion from de-icing salt, which can lead to unfavorable service conditions and vulnerability to damage. This paper examines the compressive strength, flexural-tensile strength, abrasion resistance, permeability, and spacing factor of concrete, taking into account the impact of various curing conditions, de-icing salt solutions, and mass fractions on the concrete’s freeze-thaw resistance. Two test methods, the single-face method and the fast-freezing method, were used to comparatively analyze the freeze-thaw resistance of concrete. The analysis was based on the surface scaling, water absorption rate, mass loss rate, relative dynamic elastic modulus, and relative durability index. The results indicate that the presence of salt solution significantly worsened the degree of concrete damage caused by freeze-thaw cycles. The use of freeze-thaw media, specifically sodium chloride ($\mathrm{N}\mathrm{a}\mathrm{C}\mathrm{l}$), calcium chloride (${\mathrm{C}\mathrm{a}\mathrm{C}\mathrm{l}}_2$), and potassium acetate ($\mathrm{K}\mathrm{A}\mathrm{c}$) at mass fractions of 5%, 4.74%, and 5%, respectively, had the greatest impact on the surface scaling of concrete. However, their effect on the water absorption rate was inconsistent. When the freeze-thaw medium was water, the concrete’s relative dynamic elastic modulus and relative durability index were 9.6% and 75.3% higher, respectively, for concrete cured in 20 °C—95% RH conditions compared to those cured in 0 °C—50% RH conditions. We propose a comprehensive relative durability index (${\mathrm{D}\mathrm{F}}_{\mathrm{w}}$) by combining the results of two methods of freeze-thaw tests. The ${\mathrm{D}\mathrm{F}}_{\mathrm{w}}$ of concrete cured in 0 °C—50% RH conditions was 83.8% lower than that of concrete cured in 20 °C—95% RH conditions when exposed to a freeze-thaw medium of 5% mass fraction $\mathrm{N}\mathrm{a}\mathrm{C}\mathrm{l}$ solution. To evaluate the salt freeze-thaw resistance of concrete pavement, it is recommended to use surface scaling and ${\mathrm{D}\mathrm{F}}_{\mathrm{w}}$ together.

This study investigates the feasibility of recycling waste oil shale as an alternative material into asphalt pavements in Jilin province, China. The high- and low-temperature properties of asphalt materials play important roles for asphalt pavements in seasonal frozen regions. Laboratory experiments were conducted to analyze the high- and low-temperature properties of asphalt mastics and mixtures. Results indicated that adding oil shale ash (OSA) may lead asphalt to a softer consistency and less temperature susceptibility. Also, OSA could improve high-temperature stability and enhance rutting resistance of asphalt materials, whereas the effect of OSA on low-temperature properties is insignificant by comparison. Moreover, the high- and low-temperature performances of asphalt mixtures were evaluated based on testing roads through rutting depth index, riding quality index, and indirect tensile strength test. It can be proved that the sustainable asphalt materials have better high-temperature stability and rutting resistance and also fulfill the requirements of low-temperature cracking resistance.

Oil shale ash (OSA) is a waste or by-product material, which may cause hazards for human health and environment. The objective of this paper is to evaluate the potential of OSA as partial replacement of mineral powder in asphalt mixture. For this aim, asphalt mixtures were prepared by two types of OSA wastes as partial filler replacement and compared with the control mixtures prepared with traditional mineral filler in this paper. Marshall tests were performed to investigate the volumetric and mechanical properties of asphalt mixtures. Moreover, the pavement performance including high-temperature dynamic stability, low-temperature cracking resistance and moisture stability were conducted. Results show that all required properties and pavement performance of asphalt mixture containing OSA at the optimum asphalt content (OAC) are satisfied or even improved in comparison with ordinary asphalt mixture in accordance to Chinese standard specification. The performance of asphalt mixture containing OSA was also evaluated based on a test road. In terms of environmental and economic as well as pavement performance points of view, OSA can be used instead of partial mineral filler in asphalt mixtures.

A basalt fiber-reinforced asphalt mixture can improve the engineering properties of asphalt pavement and prolong the service life of the road. However, few studies have systematically examined the composition of asphalt mixtures or the optimal ratio of fiber asphalt mastic suitable for different structural types. The effects of fiber content, filler–asphalt ratio, and asphalt viscosity on the properties of fiber asphalt mastic were investigated by orthogonal experiments to explore the reinforcement effect of basalt fiber on asphalt mastic. The optimal ratio of fiber asphalt mastic suitable for gap-graded and dense-graded asphalt mixtures was obtained by the fuzzy comprehensive evaluation (FCE) method. Meanwhile, the reinforcement effects of bundled basalt fiber (BBF), flocculated basalt fiber (FBF), polyester fiber (PF), and lignin fiber (LF) on asphalt mastic were compared and analyzed based on the optimal ratio of FBF asphalt mastic. The results showed that the optimal fiber asphalt mastic ratio suitable for gap-graded and dense-graded asphalt mixtures were that fiber content, filler–asphalt ratio, and asphalt viscosity were 3%, 1.8, and 1.1 Pa·s and 2%, 1.0, and 0.7 Pa·s, respectively. Analyzing the properties of different types of fiber asphalt mastic revealed that FBF could effectively enhance the high-temperature rheological properties and low-temperature tensile properties of asphalt mastic compared with other fibers. FBF asphalt mastic improved the asphalt rutting factor by more than four times. The tensile fracture energy of fiber asphalt mastic was more than three times that of the corresponding asphalt. The reinforcement effect of BBF was poor; it was recommended to be broken up before use.

In order to clarify the influence of the municipal solid waste incineration bottom ash (MSWI BA) content on the pavement performance of the cement-stabilized macadam, the MSWI BA with 0%, 25%, 38% and 50% content was used instead of fine aggregates. To explore the feasibility of building pavement base with cement stabilized MSWI BA, the cement-stabilized MSWI BA mixture was prepared by mixing the MSWI BA at the mass fraction of 50%, 75% and 100% with fine crushed stuff. Subsequently, the compaction test and 7 days unconfined compression test were conducted with 4%, 5% and 6% cement dosage. The compaction test, unconfined compressive strength test, splitting strength test, compressive resilient modulus test and frost resistance tests were carried out based on the long-age samples with an optimal cement dosage of 5%. Furthermore, the unconfined compressive constitutive model was established based on the test data. Afterwards, the test road was built to measure the practical effect of MSWI BA on road construction. Meanwhile, energy-saving and emission-reduction analyses were conducted on the MSWI BA road. The results showed that under 5% cement dosage, the mechanical properties and frost resistance of the mixture with different MSWI BA content both satisfied the specification requirements; during the construction, the appropriate MSWI BA content could be selected according to the requirements of different highway grades in the specification. The established segmented constitutive model could well simulate the stress–strain relationship of the mixture in the compressive process. Using cement-stabilized MSWI BA to build the pavement base was feasible, which provided not only an important reference for the engineering design but also had positive significance for promoting carbon peaking, carbon neutrality and sustainable development of highway engineering construction.

A basalt fiber asphalt mixture could improve the road performance of pavements and prolong the service life. The oil/asphalt absorption capacity of basalt fiber affects the road performance of asphalt mixtures to a certain extent. However, using kerosene as the medium to measure the oil absorption rate of bundle fibers by the vibration method, as the Chinese specifications recommends, is unreasonable. Therefore, the aim of this paper is to study the effect of the basalt fiber morphology on the oil absorption rate and the oil/asphalt absorption test methods suitable for asphalt mixtures with different structures (dense-graded and gap-graded), and to also explore the appropriate method to determine the oil/asphalt absorption rate of fiber to kerosene and asphalt. The results showed that the filamentous basalt fiber (FBF) was easier to disperse uniformly in asphalt than the bundled basalt fiber (BBF), and the oil absorption capacity of the FBF could more accurately characterize the actual working state of the fiber in the asphalt mixture. For the gap-graded asphalt mixture, the appropriate method to measure the fiber oil absorption rate is the combination of the vibration and centrifugation methods, while the fiber asphalt absorption rate is measured by the vibration method. For the dense-graded asphalt mixture, the combination of the extrusion and centrifugation methods are more reasonable to determine the fiber oil absorption rate, while the extrusion method is suitable for determining the fiber asphalt absorption rate. The concept of an effective fiber oil absorption rate is proposed to characterize the ability of fiber to adsorb kerosene in asphalt mixtures with different structures. A temperature of 160 °C is recommended as the test temperature to determine the fiber asphalt absorption rate. Kerosene as the asphalt absorption test medium could not directly reflect the ability of fiber to adsorb asphalt.