• • The Hejiawan Bridge total carbon flow is 27,482,432.11 kg CO2eq, with indirect carbon flow dominating at 92.4% (25,388,873.07 kg CO2eq), underscoring the need to target supply chain and material efficiency for decarbonization.
• • Product carbon flow constitutes 72.88% of total carbon flow, and combined with resource and energy carbon flow (25.73%), accounts for 98.61%, indicating that material selection and energy optimization are the primary levers for emission reduction.
• • The material consumption carbon flow rate of 3.91 kg CO2eq/kg is the highest among five girder bridges, signaling significant potential for material efficiency improvements through structural design and construction methods.
• • The energy consumption carbon flow rate of 13.40 kg CO2eq/kg ec is at a medium level, while a comparable bridge using cast-in-place technology exhibits a higher rate of 16.08 kg CO2eq/kg ec, demonstrating that prefabrication and structural optimization can reduce energy-related carbon intensity.