Rhythms of restoration: The Arthur Fiedler Footbridge project

The Arthur Fiedler Footbridge restoration in Boston successfully returned this iconic Brutalist structure to its original concrete appearance, thanks to MAPEI’s advanced materials and expertise. MAPEI’s products played a key role in repairing damage, improving structural integrity and ensuring long-lasting protection while maintaining the bridge’s historical significance.

The Arthur Fiedler Footbridge restoration stands as a testament to the power of innovative materials and meticulous craftsmanship. MAPEI’s comprehensive suite of products and technical expertise played a pivotal role in transforming the bridge back to its former glory. This project not only highlights the importance of preserving historical structures but also demonstrates how modern technology can be seamlessly integrated to enhance their longevity and performance.

The Arthur Fiedler Footbridge, named after the legendary conductor of the Boston Symphony and the Boston Pops, holds a significant place in Boston’s architectural and cultural landscape. Built in 1954, this footbridge is a prime example of Brutalist architecture and serves as a vital pedestrian link to the Charles River Esplanade, a state-owned park where the Boston Pops hold their renowned concerts. Over the years, the bridge had been painted a controversial salmon color, straying from its original concrete aesthetic. The restoration project aimed not only to repair cracks and spalls, but also to return the bridge to its original appearance, enhancing both its historical value and structural integrity.

The project specifications were meticulously developed in collaboration with Simpson Gumpertz & Heger (SGH) starting in Q3 2020. Following the bidding process in late 2020, mockups began in May 2021, marking the start of the restoration, which spanned from May to August 2021. The project focused on restoring and preserving the 18,000-square-foot (1 672-m²) structure, was awarded to Contracting Specialists Inc. (CSI). Their experienced team of restoration specialists comprised a dedicated crew of seven professionals.

The restoration project faced several unique challenges. Given the footbridge’s historical significance and popularity among architecture enthusiasts, the restoration was under considerable public scrutiny. The aim was to meticulously match the original concrete color, removing the unsightly salmon hue. Additionally, the project site posed logistical challenges due to its proximity to a public playground, access to community boating slips, the Esplanade’s concert Hatch Shell and Teddy Ebersol’s Red Sox Fields, as well as the need for road and footbridge closures. Safety measures included daytime work limited to specific hours, night work requiring lane closures, and dedicated safety personnel to assist playground visitors.

MAPEI on the jobsite

MAPEI played a crucial role in the restoration of the Arthur Fiedler Footbridge, providing advanced materials and solutions to meet the project’s stringent requirements.

The substrate was in poor condition, with significant spalls, severe superficial cracking, and heavily chalked and flaking paint. The restoration process began with the removal of concrete spalls and the application of rebar corrosion protection. The team used repair mortars to address the damaged areas, ensuring a stable and durable surface. Cracks were meticulously repaired using Mapeflex EMC-1 smooth, brush-grade, elastomeric patching compound and Mapeflex P1 FT one-component, nonsag, elastomeric polyurethane sealant, providing a robust foundation for the subsequent coatings.

Once the cracks were chased, cleaned and repaired, it was prime time. The crew prepared the surface for the main application, spot-priming with Elastocolor Primer AR water-based, alkali-resistant primer. This step was critical in providing a uniform finish before application of the topcoat and ensuring optimal adhesion and performance of the finish.

The primary products used in the restoration were Elastocolor Coat Fine water-based, high-build, 100%-acrylic, waterproof, fine-textured coating and Elastocolor Texture water-based, high-build, acrylic, textured coating. These coatings were color-matched to reproduce the color of the original bare concrete and provide superior protection against environmental factors such as freeze/thaw, chloride ingress and accumulation of traffic grime. The integral texture of the coatings was used to simulate the appearance of raw concrete and mask minor imperfections in the worn substrate.

Restoration projects performed in close proximity to pedestrian and vehicular traffic create their own set of challenges. The team from CSI worked diligently within the restricted work hours to minimize disruption and ensure the safety of the public. “Throughout the project, stringent safety measures were in place to protect both the workers and the public,” said Rankin Jays, MAPEI’s Coatings Business Development Leader. “The project site was securely fenced off, and work schedules were designed to minimize disruption to traffic and public access. Daytime work was limited from 7 a.m. to 4 p.m., Monday through Friday, and any work that would disrupt traffic under the bridge was prohibited. Nighttime work, which required lane closures and traffic detours, was limited to 8 p.m. to 5 a.m., Sunday through Thursday. The Esplanade includes a public playground. During daytime construction, safety personnel were present to assist families in accessing the playground. The project site was fenced off, and there was no access to it from the playground.”

The restoration of the Arthur Fiedler Footbridge was a resounding success, thanks to the collaborative efforts of SGH, MAPEI and the dedicated restoration crew from CSI. The bridge was returned to its original concrete color, much to the delight of architecture enthusiasts and the public. The use of MAPEI’s Elastocolor products not only restored the bridge’s aesthetic appeal but also provided long-lasting protection and durability.

“MAPEI is proud to have been part of this significant restoration project,” Jays concluded. “The Arthur Fiedler Footbridge is not just a functional structure but a piece of Boston’s cultural heritage. By using our advanced coating solutions, we were able to preserve its historical integrity while enhancing its durability and longevity.”