Potential environmental impact of using ultra-high performance concrete in simple, two and three-span continuous prestressed concrete bridges

The sustainable development of a country’s infrastructure is mainly affected by climate change and emissions of carbon dioxide (CO₂). New materials have been implemented to improve the sustainability of a country’s infrastructure. One of these new materials is ultra-high performance concrete (UHPC) in prestressed concrete bridges. Accordingly, this paper presents a study conducted to investigate the potential environmental impact (i.e., sustainability) of using UHPC in prestressed concrete bridges. For this purpose, three types of prestressed high performance concrete (HPC) bridges: single span, two and three span continuous bridge girders were selected from the literature. Quantities of embodied energy and CO₂ emissions of these as-designed/as-built bridges with HPC were compared to those resulted from equivalent UHPC bridge girder designs to evaluate the environmental impact of using UHPC in prestressed concrete bridges. Bulb-tee BT-63 and BT-54 girders with 15 and 18 mm diameter low relaxation strands and a cast in place concrete deck were considered. Findings of this study show that, HPC bridges have lower quantities of embodied energy and produce lower CO₂ emissions than those resulting from UHPC bridge solutions in the short term (i.e., from the beginning to the end of the construction). However, in the long term (i.e., after a 75 year period) UHPC bridge solutions provide greater environmental benefits than HPC bridges considering that UHPC has the potential to provide at least twice the service life expected from HPC.