Paving is an essential, integral component of every built structure in the United States today, especially for commercial and industrial buildings. The way that people and vehicles approach and enter a building or other structure has profound impacts on safety and security of people. It also has an important effect on the longevity of the whole structure.
That’s why, at McNeil Engineering, we make paving and the exterior setting an integral part of every structural engineering and construction management project. We know it’s essential to consider approaches, entrances, exits and traffic flow in project planning and management.
In this blog, we’re going to take a closer look at one project where paving the parking lot was key.
After a number of years, the parking lot and sidewalk at the Delta Reservations facility at the Salt Lake City International Airport had become something of a safety risk, with settled slabs, gaps between the curb and the sidewalk, broken and spalled sections, and generally damaged concrete.
The culprit, as you may have guessed, is in the climate of Salt Lake City — summer and winter freeze-thaw cycles, harsh winters and the general wear-and-tear of a busy airport.
Delta turned to McNeil Engineering for our skills and extensive experience in paving solutions as integral parts of a civil engineering project. As with every McNeil Engineering project, we began with consultations with the client. It’s essential to determine exactly what the client needs and expects from the project.
Next, we carefully examined and analyzed the existing state of the site. For that, we engaged our professional paving specialists.
“The concrete issues were mostly due to the age of the concrete,” says Carl Greene, Principal and Consulting Manager, Roofing & Paving at McNeil Engineering. “In many instances the concrete itself was in good shape, but the sub-grade beneath it had settled in some fashion, causing a sidewalk slab to sink or a vertical curb wall to tilt and pull away from the adjacent sidewalk.”
McNeil decided to divide the project into three phases. This way, only one-third of the parking lot would be unusable at any time, and employees could continue to use the parking lot during construction.
Phase I started on July 7, 2019. Phase II began after Phase I wrapped up, finishing on Aug. 20. Phase III was slated to be completed in mid-September.
“When we first arrived on site, it was obvious that the existing parking lot was flat. While that may look good when it comes to appearances, that is not so good when you need to get water off the surface,” Green explains. “Water is the single most destructive force on the planet, and when it sits on a paved surface, it begins to slowly wear down the surface prematurely.”
In total, the project involved tearing out and replacing 335,000 square feet of asphalt — that is, more than 8,300 tons of material.
The next step was to address the underlying strata, or layers, of gravel, sand and other matter, improving drainage and slopes for optimal performance and durability.
The topography or shape of the surface is critical to longevity. As Greene explains, the best approach is to mimic natural landforms to a certain extent.
“A well designed parking lot looks a lot more like the rolling hills than the prairie,” he says. “There are visible ups and downs, but nothing that is uncomfortable to walk on or drive upon. But it is very much not flat. So, when you look at the finished areas of Phase I and Phase II, they roll up and down from one side to the other, moving water off the surface as quickly as possible and depositing it into the storm drain, where it belongs.”
Each phase wrapped up with replacing broken concrete, curbs and sidewalks, shaping them for safety first, as well as proper drainage and long-term durability.
Once done, the Delta Reservations facility at the Salt Lake City International Airport will have a parking lot for its staff that is once again smooth, safe and dries quickly after rainstorms.
And it will be so for years to come. Deeper changes to the design of the under-layers will help it endure the extremes of Utah’s annual climate variations.
Midway through the project, Delta employees were already expressing more than simple satisfaction with the repairs and improvements. It’s now both easier and safer to cross the space in their vehicles and on foot, as well.
Is your employee parking lot or other pavement showing signs of age, with warping, buckling, cracking and spalling? Talk to one of our paving and roofing consultants for an honest, professional appraisal and some ideas about solutions that work for you.