Seismic performance of Fe-SMA prestressed segmental bridge columns with 3D printed permanent concrete formwork

Abstract

The integration of digital fabrication technology with prestressed segmental column construction offers significant potential for accelerated bridge construction with material-efficient design. This study aims to explore this potential by developing a novel prestressed segmental column system that utilizes permanent 3D printed concrete (3DPC) formwork for column segment fabrication. Prestressing is achieved in the proposed system by using partially bonded iron-based shape memory alloy (Fe-SMA) reinforcement. Large-scale experiments were conducted on two columns under combined gravity and lateral loading to evaluate the seismic performance and feasibility of the proposed system. The ratio of steel to Fe-SMA reinforcement in the column design was the variable considered in this study. The experimental results showed that the columns could withstand lateral drifts of up to 5% without collapse and the permanent 3DPC formwork showed no premature failure or delamination. Furthermore, the columns exhibited self-centering characteristics, maintaining a residual drift of 1% up to a target drift of 4% when the reinforcement ratio of steel to Fe-SMA rebars was 0.3. The results highlight the potential of the proposed prefabrication concept in designing material-efficient and seismically resilient bridge columns with low damage characteristics.