Multi-physics simulation–driven assessment of environmental and cost performance in ultra-high performance concrete (UHPC) bridge deck under local climate effects

Although ultra-high-performance concrete (UHPC) is known for its superior durability, its long-term performance and environmental benefits under realistic regional conditions remain insufficiently quantified. This study integrates a coupled durability–design–emissions modeling framework to address this gap. Bridge deck deterioration under regional environmental conditions and mechanical loading was investigated. The deterioration of UHPC and normal-strength reinforced concrete bridge decks was analyzed through time-dependent finite element modeling. Regional environmental factors, including periodic applications of de-icing salts and historical local temperature fluctuations in the New Jersey area and initial structural deterioration, were incorporated into the simulations. Subsequently, the total life cycle costs, including social costs, were compared. The normal-strength reinforced concrete bridge deck exhibited corrosion-induced cracking under the combined effects of mechanical loading and environmental conditions after 30 years. In contrast, the reinforced UHPC bridge deck demonstrated negligible damage, even after 100 years of chloride exposure. The simulated results suggest that the reinforced UHPC bridge deck becomes cost-effective after 60 years, assuming the initial cost of UHPC material is four times that of normal-strength concrete. Furthermore, the reduced maintenance frequency of the UHPC bridge deck resulted in resource and energy savings in addition to cost reductions. As a result, associated life cycle greenhouse gas (GHG) emissions were 2595 kg CO_2−eq per m² for the concrete bridge deck and 952 kg CO_2−eq per m² for the UHPC bridge deck, respectively. Similarly, air pollutants were further minimized because of decreased material transportation and a lower demand for raw material production over the service life.