On September 9, the 2021 Liyang-Ma’anshan Expressway (towards Ma’anshan) asphalt pavement maintenance project officially commenced. The project stretches from the Guizhuang Hub on the Liyang-Ma’anshan Expressway in the east to the Anhui provincial border in the west, covering 36.5 kilometers. It plans to complete 300 days’ worth of conventional maintenance work within 22 effective working days, paving an estimated 39,000 cubic meters of asphalt mixture, with an investment of 260 million yuan, making it the largest concentrated maintenance project in the province. Ninghang Company and Modern Road and Bridge have established a joint command center to initiate a proactive and decisive maintenance campaign.
Elevating Brand Value: First-Time Full-Project Concentrated Maintenance Construction
This concentrated maintenance project is the most intricate, involving the most procedures and complex processes. It includes 12 sub-projects, such as specialized pavement work, overlaying, non-excavation grouting, longitudinal joint treatment, settlement disease treatment, curb stone, guardrail enhancement, and more. The project integrates 67 trades and 48 procedures, employing 55 construction teams and over 1,300 workers. It also utilizes 300 types of traffic safety facilities, 117 large-scale mechanical equipment, and 360 transport vehicles and coordinates six mixing plants, indicating the project's high difficulty and technical content. To further solidify the “Su-style maintenance” brand, all participants have raised their political stance, strengthened their sense of responsibility, and aimed to serve the public's travel needs. Within the “large-scale flowing operation, small-scale interleaving” assembly line-style project organization, they have refined the “concentrated maintenance standards,” ensuring superior quality and higher efficiency through strict control over design, construction, and testing.
Expanding Diversion Breadth: First-Time Large-Scale Local Road Diversion
After multiple discussions and studies by the highway police, traffic law enforcement, and Ninghang Company, a traffic organization plan of “single-direction full closure, diverting all vehicles” was formulated. Field research, extensive data analysis, and simulation found that national and provincial highways S340, S341, and S345, parallel to the Liyang-Ma’anshan Expressway, have good traffic capacity. The traffic organization plan leverages this advantage to shoulder some diversion pressure, effectively reducing detour distances by more than 35% compared to highway detours. The project team conducted extensive early publicity across the road network to serve the public better. It provided real-time updates on construction status via popular navigation apps such as Gaode Maps and Baidu Maps, offering reasonable route planning and detour options to facilitate travel.
Deepening Maintenance Depth: First-Time Deep-Level Disease Treatment
Under the guidance of a preventative maintenance concept, this concentrated maintenance shifts from "passive defense" to "active offense." For the first time, three-dimensional array ground-penetrating radar technology is used to identify internal cracks in the asphalt pavement structure finely. This allows for precisely identifying diseases that have spread to the subbase from "line" to "surface," from partial to comprehensive, and from qualitative to quantitative. An “appearance + internal, overall + layered” detection and monitoring system is established. Using non-excavation grouting “minimally invasive” technology and fully automated construction equipment, identified diseases are repaired with precise control of grouting pressure, ensuring denser crack filling, significantly enhancing pavement structure durability, and saving 30% of construction time.
Extending Technical Length: First-Time Integration of “Industry-University-Research”
To systematically carry out pavement structural disease diagnosis, life assessment, and repair countermeasure formulation, Ninghang Company has preemptively initiated scientific research projects. They leverage concentrated maintenance's “real battlefield” to integrate multiple “industry-university-research” projects throughout construction. First, a comprehensive investigation and analysis of construction and maintenance history and geological and hydrological data are conducted to deeply study the causes of surface and subbase diseases. Second, combined with road condition performance testing and typical road section core sample tests, a systematic evaluation study is conducted on the asphalt surface layer's high-temperature stability, crack resistance, and water stability. Third, rapid non-destructive testing technology research for highway subbase diseases is conducted, proposing subbase treatment standards based on radar detection results. The "Technical Guide for Pavement Structural Disease Detection and Evaluation Based on Multi-Index Dimensions" is formulated through this project and related research, providing firsthand information for subsequent concentrated maintenance efforts.
