The way most state and local transportation departments decide whether to pave a road using concrete or asphalt most often comes down to cost over time: Asphalt is initially less expensive, but concrete lasts longer. With oil prices steadily rising over the past few decades, the cost of asphalt has also increased and reduced its price advantage over concrete. However, 93% of roads are still paved with asphalt, according to the National Asphalt Pavement Association. On the other hand, about 60% of all Interstate roads use concrete.
That distinction is just one of the many factors influencing a public transportation agency’s determination to choose a black or a grey ribbon. So, what are some of the critical decision-making factors?
Extreme weather conditions present some disadvantages for concrete.
Asphalt warms up as sunlight hits the roadway, and Mother Nature helps melt away any snow left behind by plows. Salt used for snow removal can also eat away at concrete, so some municipalities opt for a no-salt policy for the first winter or two after laying a concrete road, leading to increased traffic incidences.
Roadways with high-speed turning sections and stopping points.
Asphalt is prone to tearing under high-stress events like heavy braking. But even this is not a black and grey matter. For example, using more complex oils in asphalt mixes can reduce rutting and tearing, making the asphalt more brittle. Likewise, the wrong oil in an asphalt mixture can lead to cracking in extreme cold and rutting in extreme heat.
Asphalt is smoother & often quieter.
Concrete is often noisier because it is tined during construction to make it rough enough to provide grip. And slight shifting and settling of the many concrete slabs over time often produce that rhythmic ca-thunk ca-thunk ca-thunk sound we know so well.
Safety Directions and Coloring:
In urban areas, concrete also offers clear advantages, as stamping and color are required to increase safety at crosswalks and enhance aesthetics.
Higher & Heavier traffic.
Hefty truck volumes make concrete desirable because it simply holds up better under heavy loads. Hence, state departments of transportation tend to go with concrete on interstates.
More straightforward repairs.
Asphalt is attractive for counties and small towns because these rural areas have relatively simple equipment for patching when necessary.
Cities may opt for concrete because it requires less frequent maintenance and affords greater strength under the crush of heavier traffic volumes.
Transportation departments also factor in the time asphalt is ready to drive on once it has been rolled. Concrete typically must cure for a week after pouring. High-early-strength concrete varieties offer a 1-3 day curing period.
Ultimately cost is the primary consideration, and DOTs look at the life cycle cost over 50 years when comparing the two pavement types and their relative prices initially and in terms of maintenance.
At Aegis Asphalt Construction, we provide our clients with all the necessary information, tips, and costs to make sound paving decisions.
If you have questions about making the concrete vs. asphalt decision, contact us at 5415012309