UHPC Ultrabridge Zutphen
- Zutphen - The Netherlands
The Spikerpad Bridge in Zutphen represents a decisive upgrade of local cycling infrastructure. Located over the N348 between Zutphen and Warnsveld, the new steel truss bridge with an ultrahigh-strength concrete (UHPC) deck replaces an aging structure, offering greater clearance, minimal maintenance, and a modern, resilient design.
Project description
In this project, the existing late-1960s bicycle bridge was removed and replaced with a new steel truss bridge spanning the N348 road. The new deck is constructed with ultrahigh-strength concrete (UHSB), a slim yet robust slab system. The original abutments and support structures were retained and reinforced, while new kespen (cross beams) were added above those foundations to raise the level. The bridge is broader and positioned higher relative to the road, ensuring increased clearance for vehicles below.
Challenges of the project
One of the key challenges was achieving a higher vertical clearance without requiring full reconstruction of the foundations. The solution required precise integration of new elements (kespen) atop existing supports, and raising the deck only partially to maintain usability. Minimizing disruption to traffic during construction and ensuring safety under live roadway conditions were also significant technical constraints. Another challenge was combining slenderness with strength in the deck design, while ensuring the structure remains nearly maintenance-free over its lifetime.
Sustainability
Sustainability was embedded throughout. The reuse of existing abutments and foundations reduced material consumption and demolition waste. The use of ultrahigh-strength concrete allows thinner structural elements, thereby lowering embodied carbon. The minimal maintenance design reduces life-cycle environmental impacts. Moreover, by extending the life of infrastructure and enhancing connectivity for cyclists, the project supports more sustainable mobility.
Innovation & Technology
The project deploys UHSB (ultrahigh-strength concrete) for the deck, enabling a lightweight and slim profile. The truss structure shifts load paths laterally so that the deck is supported from the sides rather than beneath, enabling the deck to sit higher without major changes to the foundations. Fast placement techniques for UHSB panels were employed to shorten construction time and reduce disruption. The design also accounts for long-term performance, using materials and detailing that limit maintenance interventions.
FDN’s contribution
As FDN Group made the detailed calculations for the UHPC bridge deck and produced the elements with its industry partner companies in UHPC. Material testing and production and connecting the elements on site to the steel frames were all executed with FDN guidance and quality control.
Partners
- Knipscheer Infrastructuur B.V., the executing contractor responsible for demolition, assembly, and placement of bridge elements
- Provincie Gelderland and the Municipality of Zutphen, acting as clients and steering authorities