Concrete vs. Asphalt (1)

There's simply no comparison: Concrete lasts nearly twice as long as asphalt, making it a wise, long-term investment. The additional up-front costs of the concrete material itself and preparing the ground underneath the concrete can make a significant difference in the longevity of the material and the full life cycle cost comparison between concrete and asphalt.


Side by side Life cycle studies

The Michigan Department of Transportation reports that the average life expectancy of concrete pavement is 27.5 years before repairs are needed. The average life expectancy of an asphalt roadway is significantly less at only 15.5 years, according to MDOT.

Federally funded studies show concrete interstate highways across the United States last about 2.5 times longer on average than asphalt highways. Minnesota, a state that experiences even more extreme temperature swings than Michigan, has a new concrete pavement design expected to last more than 60 years with minimal maintenance.


What Makes Concrete So Durable?

Concrete is made of a mixture of aggregates, portland cement and water. Concrete may also include supplemental cementitious materials, chemical admixtures and/or fiber reinforcement. The key to achieving a durable, strong concrete is the careful proportioning and mixing of these ingredients. A well graded mix of large, medium and fine aggregates allows the cement to bind the mix more tightly increasing durability & making it more impervious to water, salt and other external forces.

Alternatively, a concrete mix with high portland cement and sand will be easy to mold and produces a very smooth surface, making it ideal for countertops or other interior decorative uses that won't be exposed to temperature extremes or heavy vehicle traffic.

A properly designed mixture is both workable for forming and has the required durability and strength when it hardens and cures. A typical mix is about 10 to 15 percent cement, 60 to 75 percent aggregate, and 15 to 20 percent water. Exterior concrete mixtures also contain air content of 5 to 8 percent which gives the concrete freeze-thaw durability.

Another critical maintenance step is to avoid deicers than contain calcium chloride or magnesium chloride. Also, never use deicers that contain ammonium sulfate or ammonium nitrate. These products will cause concrete to deteriorate faster than normal. The only recommended deicer to use is plain rock salt, which is sodium chloride.


Installation and Maintenance Matter

One of the key factors to ensure a long life for concrete is a proper subgrade and subbase during installation. The subgrade is the natural ground underneath the concrete. The material should be relatively uniform in composition and density, meaning there aren't wet or frost-susceptible areas. The subbase is a layer of sand or gravel on top of the subgrade, immediately beneath the concrete. It is imperative that the subbase be a uniform thickness and density. These layers of material work together to make sure that the loads on the concrete pavement are distributed evenly, preventing large structural cracks due to non uniform base material.

Using an approved concrete sealer after installation is the first step to successful maintenance of your concrete drive or parking area. Keeping the surface free of ice, snow, and standing water will also help it last much longer. Sealing the surface and small cracks that appear will help keep water out and minimize any potential for freeze-thaw damage. 


Longevity Levels the Costs

Nothing beats concrete’s longevity! A concrete driveway or parking lot installed on a solid base with good drainage will last 30-40 years, more than double the average life span of an asphalt product. While the initial installation cost may be higher, over the lifetime of the product, the additional up-front costs make sense.  When easier maintenance, decorative options and increased property value are factored in, concrete becomes the most cost-effective choice.