Willard Ice Parking Garage
The Willard Ice Parking Structure services the Willard Ice Building, which houses the Illinois Department of Revenue. The building and parking structure were constructed circa 1983-84. The parking structure contains a slab-on-grade and two elevated levels comprised of un-bonded Post Tension concrete slabs, concrete beams, and conventionally reinforced columns. Each level is approximately 55,000 square feet in area. Various repairs have been performed since 2000.
The Problem
In 2012, significant repairs were performed to level 3 of the structure with the intent of continuing these repairs to level 2. The extent of the necessary repair work made the continuation of the project cost-prohibitive. The parking structure was then closed and had not been in service since the termination of the repairs in 2012. The parking structure contained significant corrosion-related deterioration in the forms of concrete delaminations and concrete spalls associated with high concentrations of chloride ions resulting from repeated exposure to de-icing salts. The push to re-open the parking structure to the tenants was the impetus for the project.
Our Solution
CTL Engineering had performed a condition survey, including a corrosion assessment. Chloride exposure was very high, indicating a high risk of future corrosion. VCS was subcontracted to aid with the reinforcing layout, anode design, and QA/QC to Vector Construction. Due to PT cables in the slabs and beams, ICCP was not an option (Hydrogen embrittlement possibility). Galvashield® XP2 anodes were installed in repair areas to mitigate the potential of the halo-effect or patch accelerated corrosion. Over 10,000 Galvashield® Fusion® T2 anodes were installed in areas of sound concrete, but where conditions were optimal for active corrosion. A high burst of initial current cathodically protects the steel (not so high as to induce hydrogen embrittlement), and then a low maintenance galvanic current takes over to maintain that protected state.
The Result
The client was saved from demoing and rebuilding significant portions of the structure. We also successfully rehabilitated the parking structure with an expected service life extension of 25+ years.
Technology Used
These innovative products and technologies were used on this project.