Semi-flexible pavement (SFP) is extensively used in airport and tunnel pavements due to its high strength and toughness. As a multiphase composite material, SFP contains widely distributed aggregate-asphalt interface transition zones (ITZ) and asphalt-grout ITZ. These ITZs are the weakest areas in SFP and are susceptible to cracking during operation. To enhance the crack resistance of SFP, this paper proposes an interface immersion method to immerse the porous asphalt mixtures in a silane coupling agent before grouting. However, the cracking mechanism and interface enhancement process of the ITZ in SFP are not clear. This paper employs atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and nanoindentation (NI) to analyze the micro- and nanoscale properties of the aggregate-asphalt ITZ and asphalt-grout ITZ before and after interface reinforcement. Experiment results show that the aggregate-asphalt ITZ exhibits minimal interaction before and after enhancement, with the primary interaction occurring in the asphalt-grout ITZ, which has superior adhesion. Grout diffusion is more pronounced in the asphalt-grout ITZ, where cracks are significantly reduced after reinforcement. The element distribution in the aggregate-asphalt ITZ is uniform with a gradual transition, while the asphalt-grout ITZ shows a denser, more continuous distribution after surface immersion, enhancing mechanical properties. The width of the aggregate-asphalt ITZ remains constant (60–90 μm), while the asphalt-grout ITZ width increases notably after modification (from 60 to 90 μm to 90–120 μm). The research results can provide theoretical support for SFP design and maintenance.

Semiflexible pavement (SFP) is a composite material composed of porous asphalt mixtures and cementitious grout substances. Numerous asphalt-grout interfacial transition zones (ITZ) exist within this material and present inherent susceptibility to cracking. However, the microstructural changes within these interfaces remain inadequately understood due to the material's complex and multiphase nature. This study investigates the microstructural characteristics of the asphalt-grout ITZ and its relationship with SFP's macroscale performance, focusing on silane coupling agent modification. Atomic force microscopy (AFM) was first employed to analyze the effects of curing age, grout strength, and interfacial modification. Then, scanning electron microscopy (SEM) analysis was used to explore the correlation between the micromorphology and macroscopic mechanical properties of the asphalt-grout ITZ. Finally, a semicircular bending test was applied to test the crack resistance of SFP after interface modification. The results show that immersion of the porous asphalt mixture specimens with the interface modifier can enhance the microscopic properties of the asphalt and cementitious grout materials. The ITZ between asphalt and grout forms a double-layer structure, with smoother interfaces observed after applying the interfacial modifier. The width of the asphalt-grout ITZ may exceed 30 μm after SFP formed for 28 days. Microcracks in the asphalt-grout ITZ were significantly reduced after interface modification. These findings provide insights into proactive strategies for reducing cracking at asphalt-grout interfaces, thereby enhancing the overall performance of SFP.

Generating entanglement between distributed network nodes is a prerequisite for the quantum internet. Entanglement distribution protocols based on high-dimensional photonic qudits enable the simultaneous generation of multiple entangled pairs, which can significantly reduce the required coherence time of the qubit registers. However, current schemes require fast optical switching, which is experimentally challenging. In addition, the higher degree of error correlation between the generated entangled pairs in qudit protocols compared to qubit protocols has not been widely studied in detail. We propose a qudit-mediated entangling protocol that completely circumvents the need for optical switches at the expense of a lower success probability of the scheme. Furthermore, we quantify the amount of error correlation between the simultaneously generated entangled pairs and analyze the effect on entanglement purification algorithms and teleportation-based quantum error correction. We find that optimized purification schemes can efficiently correct the correlated errors, while the quantum error correction codes studied here perform worse than for uncorrelated error models.