Liquid asphalt is a crude product that has several uses. It makes several products we use every day more convenient and safe. Today, it’s refined, and it’s classified as a pitch.
Its origin is from petroleum crude oil. We use this for road paving. Asphalt occurs as a natural resource in several parts of the world.
How is Liquid Asphalt Created?
The part of the crude that holds the most weight is asphalt. We make gasoline from this. The asphalt is present in several types of engineering and converts to liquid. This can happen in the following three methods.
The Blending Method:
This is when asphalt blends with cutback which is a solvent from petroleum.
The Heating Method:
There are special refineries called asphalt cement plants. What emerges in the finished product is asphalt cement. Another common name is asphalt binding.
The Emulsification Process:
This is a water suspension method. Many often mistake it for tar hence the common word, tarmac. The reason for the confusion is the natural form of the asphalt. The La Brea Tar Pits in California has the natural form of this material featuring dinosaur bones that preserve intact.
Liquid asphalt is a viscous, flexible mixture. The strength and flexibility come from the binding with rock and crushed gravel. Look and you may even see seashell bits. The common name is the aggregate and there are various hydrocarbons or bitumen as we will explain later.
The History and Origin of Liquid Asphalt
We use asphalt in most places that people go without a thought about it. When you think of asphalt, you think of modern material. Something invented in recent times to accommodate modern roads and runways but this isn’t the case.
To understand this natural product in that or the refined form, it’s best to know its name around the world where it’s used most. Bitumen is a word that’s used in the UK or Canada that you’ll hear and is more accurate than pitch or blacktop which are terms used to describe asphalt in most places.
The most interesting thing about the history of Liquid Asphalt is where it all begins. It’s not in a country or with any culture. That came later on as you’ll soon discover.
In fact, it had so many uses and influenced so many cultures it’s hard to include it all here. The true beginning is in the living organisms and animals that lived and still live in the Earth.
As ancient algae and other living organisms decomposed, they left their remains that turned into the natural bitumen deposits along with petroleum and kerogen. The heat baked them into the mud deep in the Earth. Pressure, along with intense heat of above 50C is the magic that created what you now see on your roads and driveways.
You Can Find Liquid Asphalt in Various Areas of the World
It’s amazing to think of nature recycling itself and granting us a natural resource that creates our roads, highways and so much more. Some of the richest supplies in the world are in Trinidad and Tobago, Venezuela’s Lake Bermudez and the Dead Sea. There are also deposits in what’s called unconsolidated sandstones.
You can find a rich layer in Utah in the United States. Also, in an area called the “Oil Sands” in Alberta, Canada. This is where most of the deposits can be found in the world in one concentrated area.
This covers 55,000 square miles { 142,000 square kilometers}. According to Wikipedia if you put New York State and England together, this is the total area of this resource.
The cultural history begins at 6000 B.C. with the ancient Sumerians. They were in need of caulking and other waterproofing of their ships. This was the basis of their survival as a community so asphalt was like gold.
Other ancient civilizations used asphalt for the basis of the preservation of their society. Building blocks, farming irrigation, holy temples, and water supply reservoirs.
Fun Fact about Liquid Asphalt:
Everyone knows that Egyptians mummified the dead in an attempt to preserve them. This was successful in part due to asphalt. They soak the wrappings in it to fortify the process. And this was 2600 B.C..
This type of asphalt often had its uses after being found in natural deposits. It was common to find as soft material or as a rock called asphaltic coal. When the substance is through to the surface of the earth through the crust so that the wind and the heat of the sun dust it, the black, usable asphalt forms as the gases and oils evaporate.
Asphalt was always in its natural form until the early 1900s. The refined version developed from there. This had a lot to do with the emerging auto industry.
Asphalt Grading System:
Today we still use this asphalt grading system as it uses the physical properties of the asphalt binder. This is penetration and viscosity grading. Today, there is a more accurate grading system in place.
This is the PG or Performance Graded System. 49 states now use this system. The study, SHRP–The Strategic Highway Research Program, sparked the development fo the PG system.
What’s the Difference Between the Former System and PG?
The PG system is location-based. Wherever and however the asphalt will be used is what will determine the grade. The selected binders have certain expectations attached.
Judge the standards by how well the binder strength can stand up to the designated area of application. For instance, the grade for a road is may be different than that of a runway.
Reading PG Grades Made Simple:
The PG grading system is based on climate metrics of the highest and lowest temperatures. This is the Pavement Service Temperature. For instance, if you use asphalt binder on a runway then assign it as a specific quality standard.
It must be able to withstand the highest and lowest service temperature for a runway. You would repeat this with different standards for a highway or road and so on. This is based on a seven-day maximum service temperature.
PG 64/10 would be the asphalt’s description in this case. This means that under so max temp 64 and lowest at 10C. The max temp to aim for at the surface as the air temp is too high a variable. One inch below the surface is its measurement.
There must be at least a 98% confidence level in the AC working well during normal traffic use when within the aforementioned temperature range.
Polymer Modified Binders
Whenever there’s a concern for extra durability, you may need a polymer modified binder. The most common reason for using PM binders is when the surface experiences both high and low max temps.
When and What to Use Liquid Asphalt For:
There are several subsets of asphalt paving. There are also the obvious times that you use liquid asphalt and then there are the less obvious ones.
The Three Subsets of Liquid Asphalt Paving are:</h2
Municipal:
This is where roads, highways, or anything owned by the city or town. You can funnel liquid asphalt down to streets, alleyways, potholes, etc.
Residential:
Driveways anything owned by a private homeowner.
Commercial:
Anything owned by a company or anyone who profits from its existence or serves the public with the property. This can be parking lots, tennis, basketball or any sports court doesn’t require clay or other surfaces for performance. Any part of business property.
The less obvious are when patching needs to be done. This is where the grading system is the deciding factor whether it’s a large or small project, it needs to be a lasting binder.
Other less common ways to use liquid asphalt is as a waterproof sealant and even to make roof shingles and sealing a roof surface as long as it’s flat.
