I.Strength, Durability, and Safety

Protection Strength Requirements: Precisely Matching Scene Levels

Protection strength is the core indicator of a protection net and needs to be determined based on highway class, traffic volume, protection scenarios, and other factors. For highway median protection nets, they need to be able to withstand the side impact of small vehicles to prevent vehicles from crossing over. For highway slope anti-collision protection nets, the impact resistance needs to be determined based on the slope height and possible weight of falling rocks, typically requiring the ability to withstand 10-50kJ of impact energy. At the same time, the structural stability of the protection net is also crucial. The pull-out resistance of the posts and the connection strength between the mesh and the posts must meet national standards to ensure that the overall structure does not collapse under impact.

Weather Resistance and Corrosion Protection Requirements: Adapting to Complex Outdoor Environments

Highway protection nets are mostly used outdoors and face erosion from rain, snow, ultraviolet rays, industrial dust, and more, so weather resistance and corrosion protection performance directly determine their service life. Metal protection nets need to undergo strict surface treatment. The zinc layer thickness of hot-dip galvanized treatment needs to be no less than 85μm to ensure a service life of no less than 15 years in ordinary environments. In coastal humid areas or industrial pollution areas, hot-dip galvanizing + plastic spraying double treatment needs to be adopted, with a plastic spraying coating thickness of no less than 60μm to form a dense protective layer to resist salt spray and chemical corrosion. The polymer materials of composite protection nets need to have excellent anti-aging properties. After ultraviolet aging testing, the tensile strength reduction rate should not exceed 20% to ensure long-term use without embrittlement or cracking.

Safety and Environmental Protection Requirements: Balancing Protection and Humanization

While protection nets play a protective role, they need to avoid causing secondary harm to drivers and passengers. The welding points of metal protection nets need to be ground smooth, without sharp burrs. The mesh size of the mesh should be reasonably designed to prevent pedestrians or livestock from getting their heads stuck. The mesh size of highway median protection nets is usually controlled within 50mm×100mm. In addition, the materials of the protection net need to meet environmental protection requirements, and the coatings and galvanizing agents used for surface treatment need to be environmentally friendly products, without the release of harmful gases, to avoid pollution of the ecological environment along the highway.

II. Adaptability and Application

Adaptability Requirements: Fitting Highway Terrain and Scenarios

Highway terrain is complex, with different scenarios such as plains, mountains, bridges, and tunnels, and protection nets need to have good adaptability. For slope protection on mountain highways, the protection net needs to be able to adapt to changes in the slope, adopting a flexible structure or adjustable connection method to ensure close contact with the slope. For bridge protection, the protection net needs to be lightweight to reduce the bridge's load-bearing pressure, while also having wind resistance to resist damage to the protection net from strong winds. For tunnel entrance areas, the protection net needs to be seamlessly connected with the tunnel guardrail to avoid forming protection blind spots.