It all starts with a plan
A lot of work goes into planning a road. Many different experts, including engineers, landscape architects, soil scientists and more collaborate to discuss the logistics of their plan. Once they’re all in agreement, they can begin designing the road.
Blueprints for a Better Road
To design a road, surveys of the area have to be conducted. These typically use global positioning systems, laser surveys, and similar technology to conduct the surveys accurately aand efficiently.
Once a design has been finalized, your state department of transportation will hire a contractor to complete the project.
Moving the Earth Beneath Your Feet
This process lays the groundwork for the stable foundation needed for a safe, long-lasting road:
- Crews build embankments along the roadway.
- The site is excavated with bulldozers or graders.
- Base material is sprayed with water and compacted for maximum density.
- Sewers and drains are installed to optimize water runoff.
- More layers are added, moistened, and compacted until the correct height is reached.
- Once the foundation is ready, paving can begin. But first: the asphalt has to be made!
Mining the Perfect Construction Materials
- Quarry workers collect boulders of shot rock that have been blasted off of rock walls.
- Trucks take the rock to the plant, usually on the quarry site and dump their cargo into the primary crusher, which uses jaws to crush the rock to pieces.
- The primary crusher empties the crushed rock onto a conveyor belt, transporting it to an outdoor storage area.
- The rocks travel along a conveyor belt to be classified by size and tumble down a series of screens to be sorted or crushed again.
- After this last stage, most rocks are 25 cm or smaller. Anything smaller than 5 cm is put into its own pile.
- Trucks or loaders take material from each pile to separate compartments called feed bins.
Creating the Asphalt
4 most common ingredients in Asphalt
The final proportions will vary depending on what the paving asphalt will be used for.
Each bin releases a specific amount of material to a main collecting belt, then to a second belt.
The second belt takes the material to a dryer to remove all of the excess moisture.
Screening equipment then re-separates the ingredients.
The ingredients, once measured, are then added into a mixer to be blended thoroughly.
Hot liquid asphalt cement is then pumped into the mix.
The mix is then deposited into trucks to travel to the road that needs to be paved.
Paving the Road to a Smoother Ride
The finished asphalt is heated to 300°F before being spread over the roadbed. The contractor's crew works to spread, smooth, and compact the asphalt until it cools and hardens, becoming the new road!
To ensure the new road is safe for public use, the state department of transportation will order ride quality testing, which uses seismology equipment to measure vibrations of the new pavement and roadway.
Then a second drainage test is performed to double-check that there is adequate water runoff into the storm sewers.
Landscaping and grading work is completed around the work if needed to improve appearance and functionality.
Last, the white and yellow pavement markings are applied to help drivers use the new road.