Optimizing Bridge Rehabilitation: A Life Cycle Assessment and Cost Analysis of Conventional and UHPC Overlays

Bridge decks often face common issues such as concrete cracking, spalling, and deterioration. As a proactive approach to extend the bridge's service life, necessary measures must be implemented on a preventive, cyclic, or condition-driven basis. Selecting the most suitable materials for rehabilitating bridge decks is a pressing concern in extending their lifespan, underscoring the need to assess the economic and environmental performance of various overlay options. Ultra-high-performance concrete (UHPC) is one of the innovative technologies for the prevention and repair of bridge infrastructure by the USA Federal Highway Administration. UHPC requires less maintenance than traditional materials due to its very high strength and low permeability to the aggressive environment, despite the higher investment costs that may limit its deployment. It further offers enhanced performance and improved life cycle cost over conventional methods. The implementation of preventive measures could reduce the frequency of condition-driven repairs and corresponding expenditure, leading to considerably lower carbon emissions. This study performs an integrated Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) to generate a parameterized model for the preventive maintenance of bridge deck rehabilitation, considering the lifespan of the bridge as the functional unit. Different bridge deck overlay formulations are compared with conventional concrete rehabilitation. An eco-efficiency analysis was conducted to assess the performance of alternative scenarios. It was observed that despite the high initial construction cost, UHPC does not require frequent maintenance, thus proving economically and environmentally viable. The study provides a methodology to have an optimal solution considering cost and environmental impacts without prioritization or subjective weighting.