Pitkin County engineers present Redstone bridge color and finish options; integral coloring ruled out

Pitkin County engineers and the project design team briefed board members on color, finish and maintenance choices for the planned Redstone bridge replacement, explaining that the precast girders cannot be produced with integral color and that the selected color will be applied in the field after the girders are set.

The presentation, led by Andrew Knapp, Pitkin County engineer, and Mark Freimoyer, project consultant and design project manager, summarized outreach to the Crystal River Caucus and a public open house in Elk Park and presented three color options — concrete gray, red and a rustic brown — with red initially showing more support in outreach so far. Knapp said the project is tracking toward construction next year and that another public outreach event is planned for the Redstone Community Association in early August.

Why it matters: the bridge sits in a small, character-driven community where color and finish affect both preservation-minded aesthetics and long-term maintenance. The design decisions discussed determine how visible the structure will be, how quickly coatings might change appearance, and what preservation of texture and character can be achieved while meeting structural and durability requirements.

Design and finish details Mark Freimoyer said the design team contacted precasting yards to ask whether precast concrete girders could be made with integral (through-the-mix) color; "the answer was unfortunately no. They're not able to use that integral color in the precasting of these concrete girders," he said, citing tightly controlled structural mix designs and testing requirements for precast elements. Because integral color is not available for the structural precast girders, the team said color will be applied in the field after the girders are installed.

For the girders the team plans to use a structural concrete coating (a paint-like protective coating) applied to all exposed girder faces — the exterior beam sides and bottoms. "What we'll be doing inside is what they call a structural concrete coating, which is essentially concrete paint," Freimoyer said. He and other team members noted that painted coatings can fade and will need periodic reapplication if color or surface spalling occurs.

For the bridge railing the team is proposing a clear concrete sealer rather than an opaque coating. The sealer is intended to preserve a natural concrete gray appearance while protecting the surface from deicing salts and road grime. The team said modern concrete mix designs with entrained air and project materials testing will improve durability.

Testing, maintenance and application The team said they will install test color panels during construction so the community can view actual colors in site lighting before finalizing the wall-to-girder finish. For applying coatings once the span is erected, Freimoyer described typical contractor methods such as hydro-platform trucks that let crews reach under the bridge and set up containment to prevent paint or drips from entering the river.

Board members raised maintenance and aesthetic concerns — several said they preferred a natural concrete look if practicable, while others noted community preference for a colored finish ("Redstone" being a locally referenced reason for red). The presenters acknowledged that coatings fade and that a color chosen on day one will change over years, but emphasized that coatings provide protective durability even as color changes.

Outreach and next steps Knapp and Freimoyer said the design is at roughly 90 percent construction documents, that the team is in a second round of public outreach, and that construction is expected to move forward next year if schedule holds. They encouraged community members to use the project page on the Pitkin County website for project materials, schedules and email updates, and to attend the Redstone Community Association meeting planned for early August.

The presentation drew no formal vote; board members and the design team left color selection to further community outreach and test-panel results before a final decision.

Ending The project team requested and received informal board support to move ahead with final design, outreach and test-panel sampling. The team asked anyone with additional concerns to contact the project engineer directly.