When To Use Asphalt Instead of Concrete
If you’re reading this, you are probably trying to decide whether asphalt or concrete is right for your project. We hope that after reading this article, you will be ready to make the best-informed decision about which material to use.
In order to understand which to use, you should know what they are.
Both asphalt and concrete are composed primarily of something called aggregate. Aggregate is a mix of small rocks, stones, and particles. It makes up over 90% of asphalt and the vast majority of concrete as well. If you’ve ever walked across a blacktop parking lot or seen a large concrete structure, you’ve probably noticed that the loose sand, pebbles, and stones in concrete are much finer and smaller than those in asphalt paving.
Asphalt uses a petroleum-based binder, which glues everything together. It also gives asphalt it’s black appearance. Despite using oil-based products, asphalt is still relatively environmentally friendly because it is so heavily recycled.
Concrete on the other hand, uses water and (most often) Portland cement. Water mixes with the cement to create the glue that holds it together. You can read in more detail about concrete composition here.
Making your choice
You paving project probably has a great number of input factors. In order to choose the right construction materials, you will need to carefully consider each one. So we will break down each factor you must consider, and then analyze which product is right in the situation and for your priorities.
Both asphalt and concrete are highly recyclable. This means that whichever product you choose, you will be contributing to the circular economy instead of acquiring new resources from the Earth. Asphalt however, does use a petroleum-based binder. This means that making new asphalt has a much greater negative environmental impact than making new concrete. Asphalt however, can be recycled indefinitely, and is 100% recyclable. Concrete can not be recycled as many times, and only certain parts of it can be recycled anyway.
Longevity and location
However, the environmental impact of laying it is not based on recycling/making new materials alone. Other factors to consider include longevity and climate where it will be laid.
- Concrete with proper maintenance can last 40-50 years. Used in roadways, it can last 20-40 years.
- Asphalt with proper maintenance can last 30-40 years.
- In extremely hot environments (such as the US Southwest) asphalt can soften and is prone to damage. When it softens its integrity can be damaged, and poisonous runoff can be created.
Although this may not seem important, it actually is quite. Concrete has a gray/white hue, while asphalt is famously dark, and is also called blacktop.
Concrete’s lighter color confers several benefits:
- Reflects heat back to the atmosphere. It contributes less to urban heat islands that asphalt creates.
- It’s reflectivity means it requires less light at night. This saves taxpayers on paying for electricity, and decreases emissions from creating that electricity.
One of the biggest reasons asphalt is usually the choice for roadway paving is maintenance. Concrete may last longer, but both materials will develop holes, cracks, and deform over time. To repair concrete, entire slabs of concrete must be replaced. Asphalt, on the other hand, can be patched. Asphalt repair kits that fill cracks and potholes can be purchased at just about any hardware store. Of course, there are concrete repair kits too, but they are typically for residential sidewalks and non-structural surfacing.
Even when significant repairs are needed with asphalt, it can be resurfaced completely or to a very deep layer. These repairs are still much cheaper and less time consuming than replacing entire concrete blocks.
Roadway pros and cons
Although both materials can be used for roads, asphalt has won out in most locations.
- Doesn’t provide good tire grip.
- Less absorption. Gasoline, oil, and other chemicals that spill on concrete will not soak into the same way they do with asphalt. This creates runoff problems with asphalt.
- Expensive and time-consuming to repair entire blocks.
- Smoother drive for motorists.
- Better traction.
- Quieter driving than concrete.
- Can be repaired.
- Requires more repair because it wears out faster.
- Heat can damage asphalt and surrounding environs.
Both materials are made from a combination of aggregate and glue-like binder. These compounds need to be mixed and poured, after which, they harden. The process from which they turn from liquid to solid is called “setting.” This is a process that they share with many different composites, from fiberglass to Pyrex. Another one of asphalt’s advantages over concrete is that asphalt poured for a purpose similar to concrete will set much faster. Asphalt can go from an input material to a usable surface for roads in less time, and at lest cost than concrete. This feature is one of the many things solidifying asphalt’s use as the primary roadway material.
Making the right choice
Although concrete is by and far the world’s most-used building material, asphalt seems to win for roadways. However, the specific benefits and drawbacks of the use of each is understood best by professionals. If you are trying to figure out which is best for your construction, then you are in the right place. Reliable Paving has been in the paving contractor game for nearly four decades. We know how to get our paving projects done on-time, on-budget, and keep our standards to the absolute highest quality. If you aren’t sure whether concrete or asphalt paving is the right way to go, then let us know what you need. We will provide you with the best material possible for the job, and deliver the best service along the way.