Concrete Parking Lots Make Sense
Here's a new truth: concrete is cheaper than asphalt! For years we have tried to sell concrete parking lots by emphasizing the low life cycle costs based on concrete's long life span and low maintenance needs. But today asphalt prices have skyrocketed to where concrete is competitive on a first-cost basis, making the life cycle argument nearly overwhelming.
If you are trying to sell concrete or considering concrete, here are a few of the reasons why a building owner should pave his parking lots with concrete:
- Asphalt is similar to concrete except that rather than using portland cement it uses liquid asphalt as the binder. Liquid asphalt is a residue left over from refining crude oil to make gasoline. According to the Bureau of Labor Statistics, the price of liquid asphalt has increased 250% in the past 5 years, leading to a doubling of asphalt paving costs. Not only that, improvements in refining techniques mean that today only 10% of a barrel of oil ends up as liquid asphalt when in the past that was as high as 40%. This has led to severe asphalt shortages. According to an Associated Press article, more than 20 Colorado road projects and others in Washington state have been delayed simply due to asphalt shortages.
- Maintenance costs for concrete are nearly zero—only some joint sealing and annual cleaning. Asphalt parking lots need to be coated with liquid asphalt every few years and be completely resurfaced every 10 years or less. This means no business interruptions with concrete parking.
- Concrete surfaces are much lighter colored, meaning that lighting costs can be reduced—you can eliminate 3 of 10 light fixtures and still have the same level of lighting, according to Vance Pool of the National Ready Mixed Concrete Association. This creates a safer parking lot and also reduces energy costs.
- The lighter color also results in a lower temperature for the parking area during the summer, reducing the heat-island effect and lowering cooling costs for adjacent buildings. According to Pool, ambient air temperatures above a concrete parking lot can be as much as 10° cooler than an asphalt lot.
- Concrete pavements can carry heavy loads without rutting or developing potholes. With concrete's rigidity and high strength it takes only a 5-inch thick pavement to provide the same load-carrying capacity as 8 inches of asphalt.
- Concrete parking lots can be colored and textured to meet the owner's desires.
- Concrete parking lots are green—runoff is low toxicity and cooler than from asphalt surfaces and the concrete can contain recycled materials (fly ash, slag, recycled concrete aggregate). All this can yield LEED credits.
- Over the typical 20-year life of a parking lot, concrete will have very little maintenance expense while maintenance for an asphalt lot will be as much as 80% of the initial construction cost. On one Florida project, asphalt was shown to be twice the cost of a concrete lot over 20 years.
Comparing the initial cost and the cost over a 20-year life cycle, concrete is considerably less expensive. A structurally equivalent asphalt pavement is one designed to have the same load-carrying capacity. While
initial cost for structurally equivalent concrete and asphalt parking lots is comparable, concrete has very little
maintenance cost while even the best asphalt pavement needs to be resealed and resurfaced. The most
expensive pavement is a typical asphalt pavement which is cheaper to build initially, since it is under-designed
in load-carrying capacity, but that ends up with high maintenance costs.