Facility managers are often tasked with maintenance of parking structures. Made of concrete and steel, these multi-level hubs provide visitors and their vehicles with shelter from the elements and often provide access to housing or office space. However, protecting the structure itself from the constant onslaught of environmental stressors and wear-and-tear comes with its own set of challenges.
Vehicles regularly entering parking garages leave water, oil, and muck behind. Not to mention salt and deicers tracked in during the winter months that can corrode the structure’s concrete and steel support system.
An ineffective maintenance routine on a parking structure can quickly lead to costly repairs and restorations that can be disruptive to tenants and cause unexpected costs and safety concerns.
“Essentially, the goal of parking garage maintenance is to keep water and corrosives away from the garage’s reinforcing steel,” said Carter Pogue, sales/project manager with Western Specialty Contractors. “The damaging and compounding cycle of water infiltration never gets better on its own, and the longer that warning signs are ignored, the more serious and costly the repairs can become.”
The three most common types of concrete parking structures are double-tee precast, conventional cast-in-place, and post-tensioned. All three types are subject to deterioration. Western’s experts have identified five key indicators that a parking garage is in need of preventative maintenance:
• 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 rusting, rust stains along the walls, and efflorescence.
• Ponding water — Water and parking garages do not mix well, so standing water is obviously 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 is beneficial in the long run. Wear at the T-to-T joints, expansion joint failure, and flange connection deterioration are commonly found in double-tee precast structures.
• Delaminated, spalled, horizontally cracked, and vertically cracked concrete — Concrete is bound to crack at some locations. Delaminated or spalled concrete is 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 as they can lead to structural damage because they allow water to reach the garage’s reinforcing steel. This type of damage is commonly seen on post-tensioned and conventional cast-in-place concrete parking garages.
• 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 as much as 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.
Information provided by Western Specialty Contractors (www.westernspecialtycontractors.com), specialists in concrete maintenance and restoration.