Facility managers at senior living communities often are tasked with the maintenance of parking structures. An ineffective maintenance routine of these important facilities can lead to costly repairs, safety concerns and disruption to residents, staff and visitors.
Because parking structures are regularly subjected to heavy traffic, weather exposure and salt and de-icers tracked in during the winter months, their steel and concrete support systems are subjected to damaging corrosion. The warning signs can be seen on every size and type of parking structure, including the three most common types: double tee precast, conventional cast-in-place and post-tension.
The basis for any parking structure maintenance program is keeping water and corrosives away from the structure’s reinforcing steel. Once the warning signs of corrosion have begun, the problem will not get better on its own. Performing routine maintenance on parking structures will delay or avoid costly restoration, decrease liabilities, retain ideal parking volume and rates, adhere to local permitting guidelines and maintain the property’s value.
The five key indicators of parking structure damage:
- Delaminated, spalled (pictured), horizontally cracked and vertically cracked concrete. Concrete is bound to crack at some locations. Delaminated or spalled concrete occurs when a piece of concrete detaches from the structure. Along with delaminating and spalling, vertical and horizontal cracks in the concrete also represent threatening areas of weakness. These issues are problematic because they can lead to structural damage; they allow water to reach the garage’s reinforcing steel. This type of damage is commonly seen on post-tension and conventional cast-in-place concrete parking garages.
- Water leakage. Leaking water is a clear sign that a parking garage is in need of repairs. The longer the condition is left unattended, the more expensive the consequences can become. Three indicators that water leakage is occurring are exposed metals that are rusting, rust stains along the walls and efflorescence.
- Ponding water (pictured). Water and parking garages do not mix well, so standing water obviously is an issue. A simple drain installation or protective waterproof membrane will prevent future, larger problems.
- Expansion joint failure. Failed expansion joints provide another avenue for water to penetrate and reach the reinforcing steel and T-to-T connector plates. Repairing expansion joints is much simpler than resolving issues created by corroded reinforcing steel and connector plates. Detecting expansion joint problems and reacting quickly to make repairs will be beneficial in the long run. Wear at the T-to-T joints, expansion joint failure and flange connection deterioration commonly are found in double tee precast structures.
- Exposed rebar (reinforcing steel). If rebar can be seen, there is a problem that deserves swift attention. When rebar is introduced to water, it corrodes and expands up to eight times its original size. This condition usually is the result of a crack in the concrete that allows water to travel through and reach the rebar. The force of the expanding rebar causes more damage to the concrete around it, which creates greater access for water and more corrosion. It is imperative to stop this compounding cycle as soon as possible.
Recent strides in coating and sealant technology, as well as new methods for handling challenging concrete repairs, are effective tools for extending the life of parking structures and protecting its components from the elements.
Types of parking garage restoration services that may be used:
- Concrete repair and replacement
- Structural repairs
- Expansion joint installation/replacement
- Clear sealer application
- Deck coating installation
- Post tension repair (strand and button-head systems)
- Epoxy injection
- Chemical grout injection
- FRP (fiber-reinforced polymer systems)
- Cathodic protection
- Shotcrete (spray-applied concrete)
- Sacrificial galvanic anodes
It always is recommended that a facility manager work with a specialty contractor experienced in parking structure repair and restoration to identify specific problem areas, make repairs and develop a maintenance schedule.
Carter Pogue is sales/project manager for Western Specialty Contractors.
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