Asphalt, a petroleum-based product, is used everywhere. You see it in roads, driveways, and parking lots. But how much asphalt do you need for a project?
Accurately estimating asphalt tonnage is crucial to ensure you have enough material without buying too much. This saves time, money, and hassle, while ensuring your project stays on track. Calculating asphalt tonnage also helps you plan the project well.
In this article, we’ll cover how to calculate asphalt tonnage, the different types of asphalt, and any unit conversions you might need.
Asphalt basics and applications
What is asphalt?
Asphalt is a sticky, black or dark brown substance that’s used as a binder in asphalt concrete. Asphalt concrete is a composite material made of bitumen (asphalt), mineral aggregate, and a binder. You might also hear asphalt referred to as “blacktop” or “tarmac.”
Where is asphalt used?
Road construction is the main use for asphalt. For example, 94% of the 2.6 million miles of paved roads in the U.S. are surfaced with asphalt. It’s also a popular material for driveways and parking lots, as well as paths and industrial areas.
Types of asphalt
Asphalt comes in a range of formulations for different purposes. Here are some of the most common:
Hot mix asphalt (HMA)
This is the most common type of asphalt. It’s mixed and applied at high temperatures, which has both advantages and disadvantages.
Warm mix asphalt (WMA)
This type is mixed and applied at lower temperatures, which saves energy. It’s used in about a third of all road-paving projects.
Other asphalt types
There are also driveway mixes designed for residential driveways and porous asphalt, which allows water to drain through it and reduces runoff.
Calculating Asphalt Tonnage: A Step-by-Step Guide
Okay, so you’re ready to figure out how much asphalt you need. Here’s a breakdown of the steps involved:
Step 1: Measure the Job Area
First, you’ve got to nail down the length and width of the area you’re paving. If you’re working with a perfectly square or rectangular space, this is easy. But if you’re dealing with an irregular shape, break it down into smaller, more manageable sections (think rectangles and triangles), and then add up the areas of each section.
Step 2: Determine Asphalt Thickness
How thick do you want that asphalt layer to be? This depends on what you’re using it for – a driveway will likely have a different thickness requirement than a major road. Look up the recommended thickness for your specific application.
Step 3: Calculate Volume
Now, let’s get to the math. Make sure all your measurements are in feet (divide inches by 12 to get feet, or multiply yards by 3 to get feet). Then, use this formula: Volume = Length (ft) x Width (ft) x Thickness (ft). This will give you the volume in cubic feet.
Step 4: Calculate Weight
Asphalt has a density (typically around 145 lb/ft³). Use this formula: Weight = Volume (ft³) x Density (lb/ft³). This will give you the weight in pounds.
Step 5: Convert to Tons
Divide the weight in pounds by 2000 to get short tons (the standard in the US). If you’re working with metric, divide the weight in kilograms by 1000 to get metric tons (tonnes).
Optional: Account for Waste
It’s always a good idea to add a little extra to your calculation. Toss in an extra 5-6% to cover any waste that might happen during the asphalt application.
Tons vs. Tonnes
It’s important to know that there are two different units of measurement you might use when calculating asphalt tonnage: tons and tonnes.
- A ton, sometimes called a short ton, equals 2,000 pounds. The United States primarily uses this measurement.
- A tonne, also known as a metric ton, equals 1,000 kilograms. Most other countries use metric tons.
Using the wrong unit will throw off your calculations, so double-check your units before you start.
In Summary
Calculating asphalt tonnage involves several key steps: measuring the area, converting units, calculating the volume and weight, and finally, converting the weight to tons or tonnes. Getting these calculations right is crucial for project success, as it helps you save money and use materials efficiently.
If you’re working on a complex project or feel unsure about any part of the process, it’s always a good idea to consult with a professional. And remember to account for waste and to be clear on whether you’re working with tons or tonnes, as they represent slightly different measurements!