1.Steel recovery characteristics and actual recovery rate

• The actual recovery rate of building structural steel is as high as 98% (U.S. statistics for 2024)

• In rail transit equipment such as subway trains, the comprehensive recovery rate of steel and aluminum alloy exceeds 98%.

• The global average recovery rate is stable at more than 85%, much higher than other building materials.

2.The carbon reduction value of recycling

Every 1 ton of scrap steel recovered can be：

• Replace 1.6 tons of iron concentrate and reduce carbon dioxide emissions by about 1.5 tons (equivalent to the annual carbon sequestration of 300 trees).

• Save nearly 60% of energy and significantly reduce exhaust gas, wastewater, and waste residue emissions.

• If the steel recovery rate of steel structure buildings exceeds 90% after demolition (such as industrial plants reaching 90% and bridges reaching 95%), the carbon emissions in the whole life cycle are 17.5% lower than that of cast-in-place concrete buildings.

• Material production stage：The recovery rate of the main material of steel structure buildings generally exceeds 90%, while concrete is difficult to recycle, and the amount of construction waste generated is only 1/5~1/3 of the concrete structure.

• Construction phase：The steel structure eliminates the maintenance link of the support mold, and the construction period is shortened to 1/3~1/2 of the concrete structure, which significantly reduces on-site dust, noise and energy consumption.

• Demolition stage：The recycling and reuse of steel reduces the carbon emissions of the whole life cycle by 17.5% compared with concrete buildings; if combined with new energy technologies such as photovoltaic, the carbon reduction effect is more significant.

3.Additional emission reduction benefits of modular design

The modular steel structure building transfers more than 90% of the processes to the factory to achieve：

• The construction cycle is shortened by more than 50%, and the construction waste is reduced by more than 80%.

• Carbon emissions are more than 75% lower than traditional construction methods (mainly from reducing on-site operations and material losses).

4.Real case

Xiong'an New District Science and Technology Innovation Center

• Using Q690 high-strength steel, the main structure reduces weight by 20%, carbon emissions are reduced by 18%, and durability is improved at the same time.

• Replace traditional materials with high-strength steel, reduce the amount of steel used and reduce implied carbon emissions.

Macau Bridge

• The main structure uses Q500/Q690 high-strength steel to achieve lightweight structure weight and significantly reduce carbon emissions throughout the life cycle.

• The application of high-strength steel has reduced the amount of steel used per unit area, and the comprehensive cost has decreased by 15%-20% (compared with conventional steel)

The recyclability of steel structures is its core green advantage. Although the actual recovery rate does not reach the theoretical 100% due to differences in scenarios, the measured value of 65% to 95% of the industry has far surpassed that of other building materials.Through optimized design, protective demolition and digital management, its recycling efficiency will continue to improve.The key at present is to promote the synergy of the whole life cycle of the building-from the design stage to the planning of “disassembly”, in order to truly release the carbon reduction potential of the steel cycle.