Cradle-to-grave life-cycle assessment of ultra-high-performance concrete (UHPC) beams based on real-time monitoring data

Ultra-high-performance concrete (UHPC) exhibits superior fresh and hardened properties. This paper focuses on cradle-to-grave analysis of cost and carbon emission of UHPC beams based on real-time monitoring data, considering the influence of cracks on maintenance schemes. Four conventional concrete beams and twelve UHPC beams were tested under bending loads to evaluate mechanical behaviors. The investigated variables include the type of UHPC and the reinforcement ratio of beams. Three versions of UHPC materials, including a regular UHPC, a low-carbon UHPC with off-specification fly ash, and a lightweight UHPC with glass microsphere, were considered. Advanced monitoring technologies like digital image correlation and distributed fiber optic sensors were applied to monitor cracks, which play important roles in maintenance schemes. Results showed that using UHPC materials reduced life-cycle cost and carbon emission by up to 55% and 58%, respectively. Removing shear reinforcement reduced the life-cycle cost and carbon emission by up to 64% and 76%, respectively.