Towards Accelerated Bridge Construction: Ultrahigh-Performance Concrete for Precast Bridge Pier Systems

Description

Member sockets have become recognized as an effective connection method for precast concrete piers, notably for their ability to tolerate installation errors better than other connection types. However, these connections, particularly when used between precast columns and pile shafts, often require the enlargement of pile shaft dimensions to ensure connection integrity, which leads to higher material costs. Consequently, they are not widely utilized in engineering practice, especially in regions prone to high seismic activity. Ultra-high-performance concrete (UHPC), reinforced with steel fibers, presents a potential solution to this challenge due to its exceptional tensile and compressive strength and ductility.

This presentation covers our large-scale experimental studies that aim to investigate the impact of UHPC on the seismic performance of member socket connections between precast columns and pile shafts. In particular, three pier specimens with different connection details were designed, constructed, and subjected to combined axial and moment loading. The experiments focus on assessing overall and local behaviour, including failure modes, stiffness, strength, energy dissipation, and connection damage conditions. The comparison of results reveals the advantages of UHPC in mitigating damage under seismic loads and reducing the need for larger pile shaft dimensions and reinforcement, potentially leading to more cost-effective designs. Additionally, the experimental data inform the development of numerical and analytical models, laying the groundwork for a reliable seismic design method for these connections.