How much does a cubic yard of asphalt weigh? A cubic yard of asphalt typically weighs between 2.0 and 2.2 tons. This weight can change based on several factors, including the mix type, temperature, and how much it is compacted. This guide will explain how to figure out the weight of asphalt and why knowing this is important for construction projects. We will look at things like asphalt density, how to do a cubic yard to ton asphalt conversion, and how to calculate asphalt tonnage for your specific needs.
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Deciphering Asphalt Weight
Asphalt is a common material. People use it for roads, driveways, and parking lots. But asphalt is not just one simple thing. It is a mix. This mix usually has stones, sand, and a sticky black material called bitumen or asphalt cement.
The exact weight of asphalt is important for many reasons. When you order asphalt for a project, you usually order it by the ton. But when you plan how much you need, you often think about volume. Volume is measured in cubic yards. So, you need to know how to change from volume to weight.
Knowing the weight helps you:
* Order the right amount of material.
* Figure out how much the project will cost.
* Make sure the road or surface is strong enough.
* Plan the delivery and placement of the asphalt.
If you order too little, your project stops. If you order too much, you waste money. That is why knowing the weight of asphalt per cubic yard is key.
Exploring What Asphalt Is
Asphalt is a mix of stone, sand, and a binder. The binder is usually liquid asphalt cement. This cement is a product that comes from oil. It acts like glue. It holds the stones and sand together.
The materials that make up asphalt can change. This changes the weight.
* Aggregate: These are the stones and sand. They make up most of the mix (about 90-95%). The type and size of the stones matter. Heavy stones make the mix heavier. Light stones make it lighter.
* Binder: The asphalt cement is the binder. It makes up a smaller part (about 5-10%). But its weight adds to the total.
Different mixes are made for different uses. For example, a mix for a highway is different from a mix for a driveway. These differences affect the mix’s asphalt density. Density is how much something weighs for its size. A dense material is heavy for its volume.
The Importance of Weight in Asphalt Projects
Why do we care about the weight of asphalt? It seems simple, but it affects many parts of a job.
Cost and Ordering
Asphalt suppliers sell asphalt by weight, not volume. They use large scales. Trucks are weighed before they get asphalt. Then they are weighed again after. The difference is the weight of asphalt you bought.
But when engineers and builders plan a road or a driveway, they figure out how much space needs filling. This is volume. They measure the length, width, and thickness. This gives them a volume, usually in cubic feet or cubic yards.
So, the builder must change the volume (cubic yards) into weight (tons). This cubic yard to ton asphalt conversion is needed to place the order correctly. If the conversion is wrong, the order is wrong.
Project Design and Structure
The weight of the asphalt also affects how the road or surface performs.
* Load Bearing: A road needs to support the weight of cars and trucks. The weight and density of the asphalt layer are part of the design. They help make sure the road can handle the traffic.
* Compaction: When asphalt is put down, it is hot. Workers use rollers to press it down. This is called compaction. Compaction squeezes the air out. This makes the asphalt more dense. A well-compacted layer is stronger and lasts longer. Knowing the weight helps check if the compaction is done right.
Delivery and Logistics
Asphalt is delivered in large trucks. These trucks have limits on how much weight they can carry. Knowing the tons of asphalt per cubic yard helps figure out how many truckloads are needed. It also helps make sure the trucks are not overloaded.
All these points show why the weight of asphalt is a central part of asphalt work. It is not just a number; it affects costs, strength, and how the job gets done.
What Changes Asphalt Weight?
Asphalt weight is not always the same. Several things make the weight of asphalt per cubic yard change.
Type of Asphalt Mix
There are many different kinds of asphalt mixes. They use different types and sizes of stone and sand. They also might use different amounts of asphalt cement.
- Stone Size: Mixes with larger, heavier stones will weigh more. Mixes with smaller, lighter sand might weigh less.
- Stone Type: Some types of rock are naturally heavier than others. Granite is usually heavier than limestone.
- Binder Amount: A mix with more asphalt cement binder might be slightly less dense than a mix with less binder, depending on the density of the aggregates.
For example, hot mix asphalt weight can vary. Hot mix asphalt is heated before it is laid. This is the most common type for roads. Its exact weight depends on the specific recipe of materials used by the asphalt plant.
Temperature
Asphalt is usually put down when it is very hot. Hot asphalt is less dense than cold asphalt. Think of how water expands when it gets warmer. Asphalt does this too.
When asphalt is loaded into a truck at the plant, it is hot. Its volume is slightly larger, and its density is slightly lower than when it cools down and hardens. This means a cubic yard of hot asphalt might weigh a little less than a cubic yard of cold, hardened asphalt.
Most weight measurements and conversions are based on the asphalt once it has cooled and is compacted.
Compaction
This is a very big factor. When asphalt is laid, there are tiny spaces (air voids) in it. Compaction squeezes these spaces out. It makes the asphalt layer denser.
Imagine a box of marbles. There is air between the marbles. If you press them down, you can fit more marbles in the same box, or the box will weigh more if the number of marbles is the same but they are packed tighter.
When asphalt is compacted on the road:
* The volume of the layer gets smaller for the same amount of material.
* Or, if you consider a fixed volume (like a cubic yard in place on the road), the amount of material packed into it is greater.
So, the weight of asphalt per cubic yard is much higher for compacted asphalt compared to loose, uncompacted asphalt. When people talk about the weight per cubic yard for ordering or design, they usually mean the weight after it is compacted.
Specific Gravity of Materials
The stones, sand, and binder each have a specific gravity. Specific gravity tells us how dense something is compared to water. Materials with higher specific gravity are denser.
Asphalt plants test the materials they use. This helps them know the asphalt density of their specific mix. The average density of asphalt can be calculated using the densities of the materials it contains and the amount of each material.
These factors all work together. They cause the average density of asphalt to fall within a range, but not be one single, fixed number.
The Cubic Yard Explained
Before we talk about converting volume to weight, let’s make sure we know what a cubic yard is.
A yard is a unit of length, like a foot or an inch. There are 3 feet in a yard.
A cubic yard is a unit of volume. It is like a box that is 1 yard long, 1 yard wide, and 1 yard high.
Picture a box that is:
* 3 feet long
* 3 feet wide
* 3 feet high
The volume of this box is 3 feet * 3 feet * 3 feet = 27 cubic feet.
So, one cubic yard is equal to 27 cubic feet.
When you plan an asphalt project, you measure the area (length times width) and the depth or thickness.
Length (in feet) * Width (in feet) * Thickness (in feet) = Volume in cubic feet.
To get volume in cubic yards, you take the volume in cubic feet and divide by 27.
Volume (cubic feet) / 27 = Volume in cubic yards.
This volume calculation is the first step in figuring out how much asphalt you need by weight.
Converting Cubic Yards to Tons
Now we get to the core question: how do you change the volume (cubic yards) into weight (tons)?
You need to know the density of the asphalt. Density links volume and weight.
Density is defined as weight per unit of volume.
For asphalt, density is often measured in pounds per cubic foot, or kilograms per cubic meter, or sometimes directly in pounds per cubic yard.
The basic rule is:
Weight = Volume * Density
If you know the volume in cubic yards and the density in pounds per cubic yard, you can find the weight in pounds. Then you can change pounds to tons.
There are 2000 pounds in 1 short ton (the type of ton used in the US for materials like asphalt).
So, the steps are:
1. Find the volume of asphalt needed in cubic yards.
2. Find the average density of asphalt for the mix you will use. This density should be for compacted asphalt, usually given in pounds per cubic foot or pounds per cubic yard.
3. If density is in pounds per cubic foot, multiply by 27 to get pounds per cubic yard (since 1 cubic yard = 27 cubic feet).
4. Multiply the volume (in cubic yards) by the density (in pounds per cubic yard) to get the total weight in pounds.
5. Divide the total weight in pounds by 2000 to get the total weight in tons.
Let’s write this as a tons of asphalt per cubic yard formula.
First, let’s state the density range again. Compacted asphalt density is usually between 140 and 150 pounds per cubic foot.
To change this to pounds per cubic yard:
140 pounds/cubic foot * 27 cubic feet/cubic yard = 3780 pounds/cubic yard
150 pounds/cubic foot * 27 cubic feet/cubic yard = 4050 pounds/cubic yard
So, the weight of asphalt per cubic yard (compacted) is usually between 3780 and 4050 pounds.
To change pounds to tons:
3780 pounds / 2000 pounds/ton = 1.89 tons
4050 pounds / 2000 pounds/ton = 2.025 tons
Wait, earlier I said 2.0 to 2.2 tons per cubic yard. Why the difference?
The difference often comes from how the density is stated and what moisture or air voids are assumed. A commonly used figure for the average density of asphalt for quick estimates is around 145-150 lbs per cubic foot for compacted asphalt. Let’s recalculate using 150 lbs/cubic foot as a common high end for standard mixes.
150 lbs/cu ft * 27 cu ft/cu yd = 4050 lbs/cu yd
4050 lbs/cu yd / 2000 lbs/ton = 2.025 tons/cu yd
Some sources use slightly higher typical densities or averages that push the number up towards 2.1 or 2.2 tons per cubic yard for well-compacted, dense mixes with heavy aggregates. The average density of asphalt can indeed range.
Let’s check the calculation if we target 2.1 tons per cubic yard.
2.1 tons * 2000 lbs/ton = 4200 lbs
4200 lbs / 27 cu ft/cu yd = 155.5 lbs/cu ft
This density (155.5 lbs/cu ft) is possible, especially with certain types of heavy stone aggregate. So the range of 2.0 to 2.2 tons per cubic yard is a reasonable rule of thumb for estimating compacted hot mix asphalt weight.
The tons of asphalt per cubic yard formula using an estimated average density would be:
Estimated Tons per Cubic Yard = (Average Asphalt Density in lbs/cu ft * 27) / 2000
A common value used for estimating is often around 147 lbs/cu ft for compacted asphalt.
(147 lbs/cu ft * 27 cu ft/cu yd) / 2000 lbs/ton = 3969 lbs / 2000 lbs/ton = 1.9845 tons/cu yd
This is closer to 2.0 tons. Many people round up or use a slightly higher density figure for simplicity or to be safe. Using 2.0 tons per cubic yard is a common easy number for a rough estimate. Using 2.1 or 2.2 tons per cubic yard accounts for denser mixes or very good compaction.
For precise calculations, you should get the specific density from your asphalt supplier. They know the exact materials in their mix.
Calculating Asphalt Tonnage: Step-by-Step
Let’s walk through how to calculate asphalt tonnage for a project.
Imagine you need to pave a driveway.
Length = 50 feet
Width = 12 feet
Desired thickness = 2 inches
Step 1: Make all units the same.
We need everything in feet for volume calculation. The thickness is in inches. Change inches to feet.
2 inches / 12 inches/foot = 0.1667 feet
Step 2: Calculate the volume in cubic feet.
Volume = Length * Width * Thickness
Volume = 50 feet * 12 feet * 0.1667 feet
Volume = 600 * 0.1667 cubic feet
Volume = 100.02 cubic feet
Step 3: Change volume from cubic feet to cubic yards.
Volume in cubic yards = Volume in cubic feet / 27
Volume in cubic yards = 100.02 cubic feet / 27 cubic feet/cubic yard
Volume in cubic yards = 3.704 cubic yards
Step 4: Choose an estimated density or get the actual density.
Let’s use a common estimated range for hot mix asphalt weight, say 2.0 to 2.2 tons per cubic yard, for compacted asphalt.
Step 5: Calculate the total estimated weight in tons.
Using the low estimate (2.0 tons/cu yd):
Weight = Volume * Density
Weight = 3.704 cubic yards * 2.0 tons/cubic yard
Weight = 7.408 tons
Using the high estimate (2.2 tons/cu yd):
Weight = 3.704 cubic yards * 2.2 tons/cubic yard
Weight = 8.149 tons
So, for this driveway, you would likely need to order between 7.5 and 8.2 tons of asphalt. You might round up slightly when ordering to be sure you have enough, maybe order 8.5 tons.
This process covers the asphalt volume to weight conversion and helps you calculate asphalt tonnage.
Let’s do another example with a larger area, like a small parking lot section.
Length = 100 feet
Width = 50 feet
Desired thickness = 3 inches
Step 1: Convert thickness to feet.
3 inches / 12 inches/foot = 0.25 feet
Step 2: Calculate volume in cubic feet.
Volume = 100 feet * 50 feet * 0.25 feet
Volume = 5000 * 0.25 cubic feet
Volume = 1250 cubic feet
Step 3: Convert volume to cubic yards.
Volume in cubic yards = 1250 cubic feet / 27 cubic feet/cubic yard
Volume in cubic yards = 46.296 cubic yards
Step 4: Use an estimated density. Let’s use 2.1 tons/cubic yard as a middle ground.
Step 5: Calculate total weight in tons.
Weight = Volume * Density
Weight = 46.296 cubic yards * 2.1 tons/cubic yard
Weight = 97.22 tons
For this section, you would need about 97 to 100 tons of asphalt, depending on your rounding and safety margin.
These examples show how the cubic yard to ton asphalt conversion works in practice for calculating the material needed for paving jobs.
The Role of Asphalt Density
We keep talking about asphalt density. It is the key factor that changes how much a cubic yard of asphalt weighs.
Density is a property of the material itself. It tells us how tightly packed the material is.
A material with high density has a lot of mass (weight) in a small space.
A material with low density has less mass in the same space.
For asphalt, the density is set mostly by:
* The specific gravity of the stones and sand used. Heavier stone = denser mix.
* How much air is in the mix. Less air = denser mix.
When asphalt is produced at the plant, engineers design the mix to have a certain density range. When it is laid and compacted on the job site, the goal is to reach a target level of compaction. This target level is usually described by a percentage of the maximum possible density. Good compaction squeezes out air, increasing the density of the final layer.
The average density of asphalt used in calculations should reflect the expected density after it is compacted on the job. This is why figures like 145-150 lbs per cubic foot (or about 2.0-2.2 tons per cubic yard) are used for compacted asphalt. Loose asphalt, before rolling, has much more air and is less dense.
Understanding asphalt density helps predict the weight of asphalt per cubic yard for ordering and planning.
Using an Asphalt Calculator
Because figuring out volume, converting units, and applying density can be a bit tricky, many people use an asphalt calculator. These are tools, often found online or as apps, that help with the math.
An asphalt calculator usually asks for:
* The dimensions of the area you want to pave (length, width).
* The desired thickness of the asphalt layer.
* Sometimes, it asks for the type of mix or lets you enter a density value.
Based on this information, the calculator performs the steps we discussed:
1. It figures out the volume in cubic feet.
2. It converts the volume to cubic yards.
3. It uses a standard or user-provided density value to convert the volume (cubic yards) into weight (tons).
Using an asphalt calculator can save time and help avoid math errors. However, it is still important to know where the numbers come from. You should understand that the calculated tonnage is an estimate. The actual amount needed can change slightly based on the exact density of the delivered mix and how well it is compacted on site.
Always check what density the asphalt calculator is using. Some use a fixed number like 2.0 tons/cubic yard. Others might let you pick a range or enter a specific number from your supplier.
Compaction and Its Effect on Weight
We mentioned compaction before, but it’s worth looking at again because it significantly impacts the final asphalt volume to weight relationship on the ground.
When hot mix asphalt is delivered, it is loose and fluffy compared to the final road. It has many air pockets. If you were to measure the volume of loose asphalt in the truck, it would be higher than the volume it takes up after it is rolled and compacted.
During compaction, heavy rollers press the asphalt. This pushes the aggregate particles closer together and squeezes out most of the air.
- Before Compaction: Lower density (more air), Higher volume for a given weight.
- After Compaction: Higher density (less air), Lower volume for the same weight.
When you order asphalt by the ton, you are buying a certain weight of material. When you lay it, you are filling a certain volume (the area multiplied by the thickness). You need enough tons to fill that volume after it is compacted to the required density.
The density figures (like 2.0-2.2 tons per cubic yard) used for ordering are for the compacted volume. You must ensure you order enough material to achieve the target thickness and density on the ground. If you don’t compact enough, your layer will be thicker but weaker and less dense than planned. If you compact too much (rare, but possible), you might end up with a thinner layer.
Good compaction is vital for the performance and lifespan of the asphalt surface. It ensures the material reaches its intended asphalt density, which in turn means the ordered weight correctly filled the planned volume.
Estimating Asphalt Needs: Beyond Simple Math
The length * width * thickness calculation gives you a basic volume. But real-world projects have more things to think about when you calculate asphalt tonnage.
- Irregular Shapes: Not all areas are perfect rectangles. You might have curves or odd shapes. You need to break these down into simpler shapes or use special measuring techniques to find the volume.
- Existing Surface: If you are paving over an old surface, it might not be perfectly flat. You might need more material in some spots to level it out. This is sometimes called a “leveling course.”
- Waste: There is always some waste on a construction site. Some asphalt might be left in the truck, spill over, or be trimmed off the edges. It is wise to add a small percentage (like 5-10%) to your total tonnage to account for this.
- Compaction Variability: While you aim for a target density, compaction might not be perfectly uniform across the whole area. Some spots might be slightly less or more dense.
Experienced contractors consider these things. They might add a little extra material to their order to be safe. This is why the calculated amount is a good starting point, but some judgment is often needed.
Using the tons of asphalt per cubic yard formula gives you the theoretical amount. Adding a buffer helps ensure you complete the job without running short.
Tips for Ordering Asphalt
Based on everything we have covered about asphalt volume to weight, here are some tips for placing your order:
- Know Your Dimensions: Measure the length, width, and planned thickness accurately. Double-check your measurements.
- Convert Units Carefully: Make sure all measurements are in the same units (usually feet) before calculating volume. Convert volume to cubic yards correctly (divide cubic feet by 27).
- Confirm Density with Supplier: Ask your asphalt supplier for the expected compacted density of the specific mix you are ordering. They might give it in pounds per cubic foot or tons per cubic yard. This is the most accurate way to do your cubic yard to ton asphalt conversion.
- Use a Reliable Conversion Factor: If you cannot get the exact density, use a common rule of thumb like 2.0 to 2.2 tons per cubic yard for compacted asphalt. Using 2.0 is simple but might leave you short. Using 2.1 or 2.2 is safer for dense mixes.
- Account for Waste and Leveling: Consider adding a percentage (e.g., 5% to 10%) to your calculated tonnage to cover waste and any needed leveling.
- Use an Asphalt Calculator: An online asphalt calculator can help, but make sure you understand the density value it uses.
- Communicate with Supplier: Tell your supplier the area size and desired thickness. They are experienced and can help confirm if your calculated tonnage seems correct.
- Consider Lift Thickness: Asphalt is often laid in layers called lifts. Your total thickness might be one or two lifts. This doesn’t change the total volume or weight needed, but it’s part of the paving plan.
By following these steps, you can make an informed decision about how many tons of asphalt to order based on your required volume and the weight of asphalt per cubic yard.
A Closer Look at Mix Types and Weight
Different types of asphalt mixes are designed for different jobs. The recipe changes, and this affects the hot mix asphalt weight.
- Dense-Graded Mixes: These are the most common. They have a range of stone and sand sizes packed tightly together. They are used for wearing surfaces on roads and driveways. Their density is typically in the 145-150 lbs/cu ft range (around 2.0-2.2 tons/cu yd) when compacted.
- Open-Graded Mixes: These mixes have fewer fine materials and more air pockets when compacted. Water can drain through them. They are less dense than dense-graded mixes. Their weight per cubic yard would be lower.
- Stone Matrix Asphalt (SMA): This mix has a high amount of coarse stone with a rich mortar of asphalt binder and fine material. It is very durable and often used on highways. It can be slightly denser than standard dense-graded mixes, potentially pushing towards the higher end of the 2.0-2.2 tons/cu yd range or even slightly higher, depending on the stone.
- Cold Patch Asphalt: This is a temporary mix used for fixing potholes. It uses a different type of binder that works at lower temperatures. It is not designed for high strength or density and would have a different weight per cubic yard than hot mix asphalt.
When you order asphalt, you specify the type of mix needed for your project. The supplier can provide the expected compacted density for that specific mix, which is crucial for accurate asphalt volume to weight calculations.
Table: Estimated Asphalt Weights
Here is a simple table showing estimated weight of asphalt per cubic yard based on common densities for compacted hot mix asphalt weight.
| Asphalt Density (lbs/cu ft) | Asphalt Density (lbs/cu yd) | Estimated Weight (Tons/cu yd) | Notes |
|---|---|---|---|
| 140 | 3780 | 1.89 | Lower end, potentially less dense mix |
| 145 | 3915 | 1.96 | Common average for many mixes |
| 147 | 3969 | 1.985 | Often rounded to 2.0 tons/cu yd |
| 150 | 4050 | 2.025 | Higher average density |
| 155 | 4185 | 2.09 | Denser mixes, heavy aggregate |
| 160 | 4320 | 2.16 | Very dense mixes, heavy aggregate |
This table reinforces that the average density of asphalt leads to a range of tons of asphalt per cubic yard. Using a figure like 2.0 to 2.2 tons per cubic yard is a practical way to estimate, covering the typical range for compacted pavement.
Summing Up Key Ideas
- Asphalt is sold by weight (tons), but projects are planned by volume (cubic yards).
- Converting volume to weight requires knowing the asphalt density.
- Compacted asphalt weighs more per cubic yard than loose asphalt. Calculations are usually for compacted volume.
- A cubic yard is a box 3 feet by 3 feet by 3 feet, equal to 27 cubic feet.
- The weight of asphalt per cubic yard for compacted hot mix asphalt is typically between 2.0 and 2.2 tons.
- This range is due to differences in the type of stones used and the exact mix design (hot mix asphalt weight).
- You can calculate asphalt tonnage by finding the volume in cubic yards and multiplying by the estimated or known density in tons per cubic yard.
- The tons of asphalt per cubic yard formula is roughly: (Volume in cu yd) * (Density in tons/cu yd) = Total Tons.
- An asphalt calculator can help with the math.
- Always talk to your supplier for the most accurate density figure for their specific mix.
- Add a little extra material (5-10%) for waste and leveling.
Knowing the relationship between asphalt volume to weight is essential for anyone working with this common material. It helps ensure projects are planned and completed correctly and within budget.
Frequently Asked Questions (FAQ)
Here are answers to some common questions about asphalt weight and volume.
h4>What is the standard weight of asphalt per cubic yard?
A standard, general estimate for the weight of compacted hot mix asphalt is about 2.0 to 2.2 tons per cubic yard.
h4>How do I convert cubic yards to tons for asphalt?
To convert cubic yards to tons, you need to know the density of the asphalt. You multiply the volume in cubic yards by the density in tons per cubic yard. For example, if you have 5 cubic yards and the asphalt weighs 2.1 tons per cubic yard, you need 5 * 2.1 = 10.5 tons.
h4>How many pounds does a cubic foot of asphalt weigh?
A cubic foot of compacted asphalt typically weighs between 140 and 150 pounds. This weight changes based on the mix.
h4>Does the type of asphalt mix change the weight?
Yes, definitely. Different mixes use different kinds of stone and sand, which have different densities. This changes the overall asphalt density and thus the weight of asphalt per cubic yard.
h4>Why is asphalt sold by weight and not volume?
Asphalt is sold by weight because its volume changes with temperature (it expands when hot) and how much air is in it (compaction). Weight is a more stable measurement than volume for material ordered from a plant.
h4>How does temperature affect the weight per cubic yard?
Hot asphalt is slightly less dense than cold asphalt. So, a cubic yard of hot asphalt right from the plant weighs a little less than that same amount of material after it cools down and is compacted on the road. Calculations for ordering usually use the expected density after cooling and compaction.
h4>How does compaction affect the weight per cubic yard?
Compaction squeezes air out of the asphalt. This increases the density of the material in place. The weight of asphalt per cubic yard is much higher for compacted asphalt compared to loose asphalt. Calculations for ordering must use the compacted density.
h4>Can I use an online asphalt calculator?
Yes, an online asphalt calculator can be helpful. Just make sure you know what density value it is using for the conversion. It’s best to confirm the density with your asphalt supplier if possible.
h4>What factors should I consider when estimating asphalt tonnage?
Consider the area size, desired thickness, the expected compacted density of the mix (get this from your supplier if you can), and add a little extra material (like 5-10%) for waste, spills, or leveling needs.