Anti-corrosion treatment of steel structures extends their service life. The building steel plate with a hot-dip galvanized coating of 275g/㎡ (Z275 grade) has a rust resistance life of up to 50 years in C5 grade industrial corrosive environments, which is 10 times longer than that of ordinary carbon steel. The Hong Kong-Zhuhai-Macao Bridge has adopted this type of Galvanized plate to manufacture the guardrail brackets. The salt spray test has passed the 4,800-hour standard (ISO 9227), and it is expected that the maintenance cycle will be shortened by 80%. Measured data shows that a 0.12mm zinc coating can effectively resist an average annual corrosion rate of 0.8μm, reducing the total life cycle cost by 42% in coastal projects.
Resistance to extreme weather in the roofing system. The 1.2mm thick aluminum-zinc coated steel plate (55% aluminum-zinc alloy layer) has a reflectivity of 75%, reducing the surface temperature of buildings by 17℃ and increasing the energy-saving rate of air conditioners by 24%. The T3 terminal of Shenzhen Airport has applied 120,000 square meters of wavy galvanized roof panels, with a wind pressure resistance rating of 4.5kPa (EN 14782), successfully withstanding the impact of super Typhoon Mangkhut of level 17. Its 0.04mm dense passivation layer enables the salt spray resistance to exceed 2000 hours, far surpassing the municipal standard requirement of 1200 hours.
The load-bearing structure has achieved a breakthrough in lightweighting. The yield strength of G550 high-strength galvanized steel sheet is 550MPa. When used for columns and beams in prefabricated buildings, it reduces weight by 38%. The actual measurement of the Xiongan New Area Civic Service Center project shows that the 3mm thick galvanized square tube column has a 64% smaller cross-section than the traditional concrete column, while its load-bearing capacity has increased by 12%. Seismic tests show that the displacement Angle of the galvanized steel frame structure is only 1/400 (the limit value of GB 50011 standard) at an acceleration of 0.4g, and the energy consumption coefficient increases to 0.15.
Fire safety builds a key barrier. The 0.7mm galvanized fireproof air duct passed the BS 476 Part 22 standard test and maintained its integrity in an 800 ° C flame for 120 minutes. The Shanghai Tower adopts this type of air duct system, with a flue gas permeability of less than 1.8m³/h·m² (only 1/9 of that of concrete pipes). Accident analysis shows that the melting point of galvanized cable trays is 419℃, and they can resist fire for 0.6 seconds during a short circuit, thus buying critical response time for the fire protection system.
Modular buildings enhance construction efficiency. The 0.8mm galvanized light steel keel wall was adopted, and the daily installation progress reached 85 square meters per team, which was 15 times faster than the masonry project. Data from the Country Garden project shows that the installation error of prefabricated galvanized stair treads (2.5mm thick) is ±0.8mm, and the on-site adjustment time is reduced by 92%. The standard parts interchangeability rate was 99.3%, enabling the main structure of a 2,000-square-meter apartment building to be capped within 30 days.
The photovoltaic system foundation extends the lifespan of assets. Galvanized steel plates (Z150 grade) for solar brackets, combined with magnesium anode protection, ensure a 25-year service life in an environment with a pH range of 5.5 to 12. Monitoring of photovoltaic power stations in Ningxia shows that the annual corrosion rate of galvanized brackets is only 0.4μm, reducing maintenance costs by 76% compared to ordinary brackets. Its surface friction coefficient is 0.12 (ASTM D1894), and the anti-slip bearing capacity exceeds the design value by 200%.
Acoustic engineering optimizes the living experience. The perforated galvanized sound-absorbing board (with a hole diameter of 1.2mm/ opening rate of 28%) has a sound absorption coefficient of 0.95 in the mid-frequency band (ISO 354 standard). The application case of the National Centre for the Performing Arts shows that the 8mm composite galvanized sound barrier reduces the indoor reverberation time from 2.8 seconds to 1.1 seconds and improves the speech clarity by 42%.