Lifecycle carbon emissions of reinforced concrete Buildings: Assessment and mitigation Priorities

The construction industry is a major contributor to global carbon emissions, yet existing studies often provide only policy-level guidance without quantitative reduction targets, and domestic research is limited by the scarcity of systematic building-level case studies. This study combines macro-level construction carbon trends with building lifecycle surveys to identify high-emission stages and propose practical mitigation strategies. A construction industry carbon emission model, based on National Bureau of Statistics data, was used for scenario analysis and trend prediction. Results show that embodied and operational carbon account for 59.85 % and 40.15 % of total emissions, with material production and operation stages contributing 93.43 % (R² = 0.988). Achieving carbon peaking by 2030 requires annual reductions of at least 1.161 × 10¹⁰ kg CO₂e, including 6.95 × 10⁹ kg embodied and 4.66 × 10⁹ kg operational carbon. Building-level case studies of eighteen reinforced concrete structures reveal that embodied and operational carbon account for 21.12 % and 78.88 %, respectively; material production contributes 19.87 % of total emissions, with steel and concrete responsible for 92.7 % of this stage, and civil works account for 99.73 % of construction-phase emissions. Optimizing materials, construction processes, and engineering practices allows effective emission reduction within the engineer's control, providing actionable guidance for the construction industry's low-carbon transition.