The Challenge
At the center of the University of Illinois Urbana-Champaign campus sit two parking structures that quietly support daily campus operations. Built in 1970, the C7 and C10 garages serve university leadership, staff, and visitors in one of the campus’s busiest areas.
After decades of exposure and advancing deterioration, the University faced a major decision: demolish and replace the structures, or determine whether they could safely and effectively serve the campus for another 20 years.
Walker was engaged to perform a comprehensive structural assessment and develop a long-term strategy balancing cost, safety, sustainability, and operational continuity — all while keeping these heavily used facilities functioning throughout construction.
Investigating the Structures
Our forensic investigation uncovered extensive deterioration typical of aging post-tensioned concrete structures, including widespread corrosion within the slab post-tensioning system caused by long-term moisture intrusion.
But the most significant finding wasn’t just deterioration. It was complexity.
The parking structures were built using a historical 1960s structural system that combined precast and post tensioned single-tee beams with unbonded post-tensioned slabs and minimal reinforcing steel. Repairing the damaged slab post tensioning would require working around corroded live tendons and large concrete removals to extract the heavily corroded strands.
The team also identified serious façade concerns, including deteriorated brick anchorage and backup walls that were unreinforced and structurally deficient.
A Smarter Alternative to Replacement
Rather than recommending demolition, Walker developed a rehabilitation strategy that preserved the existing structures while modernizing them for future campus needs.
The solution centered on strengthening the slabs from the exterior, rather than demolishing and repairing slab tendons. We designed a new galvanized structural steel support system installed beneath the concrete slabs, bypassing compromised post-tensioning and restoring structural capacity without requiring full reconstruction.
The multi-year rehabilitation program included:
- Structural slab and beam strengthening
- Comprehensive waterproofing and concrete restoration
- Masonry stabilization and façade anchorage upgrades
- Full MEP system replacement
- New LED lighting, security systems, and fiber optic infrastructure
- EV charging stations and upgraded wayfinding
- Emergency generator backup power
- Stair tower reconstruction and accessibility improvements
Solving the Elevator Challenge
One of the project’s most difficult components involved adding accessibility to the C10 structure—a structure that was originally designed without an elevator.
The challenge was more complicated than simply “adding a tower.” The new six-story elevator structure had to be inserted into an extremely confined footprint surrounded on three sides by existing walls and active campus infrastructure.
To make it work, Walker designed a heavily reinforced concrete elevator tower supported by a mat foundation while carefully coordinating around existing deep foundations and below-grade conditions.
Construction crews excavated more than 34 feet below grade within a footprint of only about 120 square feet. Due to the tight site constraints, excavation equipment had to be lowered directly into the shaft area while soil was removed bucket by bucket.
The tower ultimately required:
- 44,000 pounds of reinforcing steel
- 375 cubic yards of concrete
- A hydraulic elevator piston drilled more than 62 feet deep
- Complex waterproofing systems for below-grade protection
- Structural transfer beams to navigate large wall openings and existing foundations
Even sourcing brick that matched the original façade became part of the challenge.
The result was a fully integrated accessibility solution constructed within one of the most constrained areas on campus.
Delivering Complex Rehabilitation in an Active Campus Environment
Construction was completed in phases to maintain parking availability for campus operations and university staff. Over the course of the project, teams installed:
- 1,600 structural steel strengthening beams
- More than 5,000 anchors and steel connections
- 556,000 pounds of high-strength grout
- Hundreds of slab penetrations around active post-tensioning systems
The project also included extensive coordination for new telecom and fiber infrastructure routed from more than a block away within a tightly constrained construction schedule.
The Result
Completed over an eight-year effort, the $20 million rehabilitation transformed two aging parking structures into modernized campus assets positioned for decades of continued service.
By choosing restoration over replacement, the University reduced capital costs, minimized disruption, and extended the life of critical infrastructure while improving accessibility, safety, technology integration, and long-term sustainability. By not locking down the land for 50+ years with a new development, this rehabilitation approach allowed the University flexibility in the use of the land in the future.
Today, C7 and C10 demonstrate how thoughtful engineering and strategic rehabilitation can revitalize aging structures without sacrificing performance, functionality, or user experience.