Naitian Zhang

In response to the lack of a systematic, data‐driven evaluation method for the length of temporary median openings in expressway reconstruction and expansion, this study develops an intelligent assessment framework that integrates VISSIM based on microscopic simulation, CRITIC objective weighting, and four parallel assessment modules: TOPSIS, One‐Dimensional Cloud Model, MDCM and MDFICM. Three typical opening configurations‐lane reduction, lane expansion, and lane conservation‐are evaluated under low, medium, and high saturation levels with opening lengths of 100 m, 200 m, and 300 m. Four performance indicators‐delay, conflict rate, speed difference, and fuel consumption‐are extracted from simulation monitoring. Cross‐validation revealed that in the lane conservation scenario, all four modules unanimously recommended 100 m across all saturation levels; in the lane reduction scenario, optimal lengths varied by saturation, i.e., 100 m was recommended under low and high saturation, while 300 m was preferred under medium saturation; in the lane expansion scenario, all four modules consistently recommended 100 m under medium saturation, whereas recommendations diverged under low and high saturation; at low saturation, 100 m received the greatest support (2 of 4 modules) without a majority consensus, while at high saturation, 100 m was supported by three of the four modules. The parallel multi‐module architecture effectively mitigates single‐model bias by enabling cross‐validation from complementary theoretical perspectives. The proposed framework provides a robust, data‐driven decision‐support tool for temporary traffic organization design in expressway reconstruction and expansion.

Filling-type large-size cement-stabilized macadam (F-LSBC) is a promising base material for mitigating reflection cracking in semi-rigid pavements. However, its engineering application is hindered by the challenge of balancing strength, crack resistance, and construction adaptability. More fundamentally, the relationship between micromechanical features—especially the interfacial transition zone (ITZ)—and the macroscopic behavior of filling-type cement-stabilized composites remains insufficiently understood. This study used conventional cement-stabilized macadam (CSM) as a reference and combined nanoindentation with macro-scale mechanical, fatigue, and drying shrinkage tests to clarify the micro–macro mechanisms of F-LSBC. Results show that the ITZ in F-LSBC exhibits substantially lower elastic modulus (reduced by 60–75%) and hardness (reduced by 55%), along with greater porosity and phase volume fraction than CSM. Cluster analysis revealed a thicker ITZ (55–90 μm vs. 40 μm), indicating notable interfacial weakening. These microstructural features lead to reduced strength and fatigue life. Nevertheless, due to its high coarse aggregate content and weak-interface-induced “crack-without-displacement” mechanism, F-LSBC demonstrates enhanced shrinkage resistance, with drying shrinkage reduced to 81.36% of that of CSM at 180 days. The findings emphasize the key role of ITZ characteristics in determining performance and suggest that improved interface engineering could enhance durability and shrinkage control in pavement bases.

With the aging of China’s expressway network, the number of maintenance projects continues to increase, and issues such as construction safety, driving risk, and traffic efficiency have become increasingly prominent. This paper systematically reviews relevant research progress from four aspects: safety characteristics, traffic capacity, work-zone layout, and speed limit management. The review indicates that Western scholars have made extensive use of rich data resources—such as traffic parameters and accident records from expressway maintenance road sections—and have developed relatively systematic and well-established research frameworks in theoretical analysis, practical application, and evaluation methods. In contrast, Chinese studies have mainly relied on specific maintenance projects, commonly employing on-site investigations and traffic simulations to address particular problems, with limited systematization and generalization. Looking forward, it is essential to further strengthen the standardized collection and statistical analysis of traffic data (including accident data) for expressway maintenance road sections. Meanwhile, for complex scenarios such as multi-lane segments, special road sections, reconstruction and expansion sections, as well as extreme climatic conditions and nighttime operations, comprehensive research should be conducted by leveraging new-generation driving simulation, big data analytics, and artificial intelligence technologies, thereby providing scientific support and methodological foundations for building a systematic theoretical framework for traffic safety in expressway maintenance road sections.

To address the challenge of obtaining core samples directly from the field for low-temperature crack resistance tests of asphalt mixtures, this study utilizes the not-notched semi-circular bending (NN-SCB) creep test as a novel evaluation method. The feasibility of this method is discussed and validated through both simulation and experimental testing. First, ABAQUS software was employed to model the NN-SCB creep test, with various viscoelastic and creep load parameters analyzed to evaluate the percentage of tensile creep dissipation energy in asphalt mixtures with different characteristics. The results indicate that the tensile creep dissipation energy consistently accounts for approximately 31.5% of the total creep dissipation energy across all tested asphalt mixtures, irrespective of their properties. Five types of asphalt mixtures were designed, three of which incorporated Reclaimed Asphalt Pavement (RAP) as the aggregate base. These mixtures were subjected to both NN-SCB and Thermal Stress Restrained Specimen Test (TSRST) methods. The experimental findings demonstrate that the tensile creep dissipation energy in the NN-SCB test provides a robust and consistent measure of low-temperature crack resistance, with results closely aligning with those from TSRST. Specifically, the tensile creep dissipation energy of mixtures containing 40% RAP showed a significant reduction in low-temperature cracking resistance, with a 41.3% lower creep rate compared to the virgin asphalt mixture. The study confirms the feasibility of using NN-SCB and tensile creep dissipation energy as reliable indices for evaluating the low-temperature crack resistance of asphalt mixtures.

This paper aims to incorporate the fractional derivative viscoelastic model into a finite element analysis. Firstly, based on the constitutive equation of the fractional derivative three-parameter solid model (FTS), the constitutive equation is discretized by using the Grünwald–Letnikov definition of the fractional derivative, and the stress increment and strain increment relationship and Jacobian matrix are obtained by using the difference method. Subsequently, we degrade the model to establish stress increment and strain increment relationships and Jacobian matrices for the fractional derivative Kelvin model (FK) and fractional derivative Maxwell model (FM). Finally, we further degrade the fractional derivative viscoelastic model to derive stress increment and strain increment relationships and Jacobian matrices for a three-component solid model and Kelvin and Maxwell models. Based on these developments, a UMAT subroutine is implemented in ABAQUS 6.14 finite element software. Three different loading modes, including static load, dynamic load, and mobile load, are analyzed and calculated. The calculations primarily involve a convergence analysis, verification of numerical solutions, and comparative analysis of responses among different viscoelastic models.