Assessing the carbon reduction potential of high-performance concrete in urban construction

This study evaluates the environmental and economic performance of four high-performance concretes (HPCs) in urban construction, aiming to support structural optimization and low-carbon development. The selected HPCs include Ultra-High Performance Concrete (UHPC), Coarse Aggregate UHPC (UHPC-CA), Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC), and Ultra-High Performance Geopolymer Concrete (UHPGC). A life-cycle-based evaluation framework is established based on a real 11-story reinforced concrete frame column system. Four high-performance concrete replacement schemes are assessed under equivalent load-bearing requirements to compare carbon emissions, material costs, and structural performance from material production to on-site construction. Results show that UHPC-CA reduces emissions by 17 % and cost by 8 %, while maintaining mechanical capacity. UHPFRC improves axial capacity by 142.5 % with a moderate 8 % cost increase and an overall emission reduction. UHPGC achieves the highest carbon savings, reducing emissions by 35.3 % through the use of a cement-free geopolymer binder. This study is among the first to combine environmental, economic, and structural indicators in a comparative assessment of multiple HPCs within realistic construction scenarios. It also incorporates regional emission and cost data from five major Chinese cities, enhancing the practical relevance of the results. The findings provide valuable insights for the promotion of green concrete technologies and the implementation of sustainable urban building strategies