The use of asphalt started thousands of years before the founding of USA. Mesopotamians are credited as the first to use asphalt to waterproof temple baths and water tanks. It was also used by Phoenicians to waterproof their merchant ships. Asphalt was first used for road building in Babylon at around 625 BC. The Romans took up the road system from Carthaginians and built roads for easier travel by the military.

Asphalt Roads in Modern History

John Metcalf, an Englishman was built the first asphalt roads in Yorkshire in late 1700’s. He built about a hundred and eighty miles. Later on, in early 1800’s, Thomas Telforld built over nine hundred miles of roads in Scotland. This art was perfected by John Loudon Macadam, who used broken stones and asphalt to construct his roads. This method was adopted by builders that led to the name ‘tarmacadam’ shortened as ‘tarmac’ pavements

Asphalt Roads in America

In 1870, a Belgian chemist, Edmund J DeSmedt, laid the first asphalt pavement in US at Newark. He later used fifty four thousand square yards of sheet asphalt from Trinidad Lake to pave Pennsylvania Avenue in Washington. In the same year, Cummer Company opened hot mix production facilities. The following year, 1871, Nathan. Abbott of Brooklyn, N.Y filed the first asphalt patent.

In 1900, a patent for ‘Bitulithic’ pavement was filed by Frederick J. Warren. It was a mixture of bitumen and aggregate. The name Bitulithic was derived from ‘bitumen’ and ‘lithos’ a Greek word for rock. In 1901, Warren Brothers built the first asphalt facility in East Cambridge, Mass.

By 1907, asphalt from refined petroleum has outstripped natural asphalt by both production and usage. Automobiles became increasingly popular increasing demand for more and better pathways and roads. This in turn led to a number of innovations in asphalt laying. There were also strides made towards mechanization with introduction of drum mixers, concrete mechanical spreaders and asphalt laying machines. Asphalt technology continued improving, more so during World War II in 1942. This was driven by the need for a better surface that could hold the heavy loads of military aircraft and its cargo.

In 1955,road construction firms formed The National Bituminous Concrete Association, a forerunner of National Asphalt Pavement Association.(NAPA).  It main mandate was to undertake a quality improvement program. In its execution, the association sponsored asphalt testing in private testing labs and at universities.

In 1956, the Congress passed the Interstate Highways Act. It allotted fifty one billion dollars to states to construct roads. This greatly improved road construction technologies since contractors required better and bigger equipment. Machinery such as electronic leveling controls, extra-wide finishers and vibratory steel wheel rollers have since been manufactured.

There was a national energy crisis in 1970’s that led to a rethinking of natural resource conservation. Today, asphalt is one of the most recycled materials with over seventy million metric tons recycled every year.

In 1986, The National Centre for Asphalt Technology was established by NAPA. It continues to test and improve asphalt. It is now a leading asphalt research center. From year 2002, asphalt is no longer considered a hazardous air pollutant by the EPA.

To understand the origins of asphalt concrete, one has to go all the way back to the 6th century BC in Babylonia where the first asphalt roads were laid. It was not until the 18th century, however, that asphalt roads first began to become more widely used and tested for reliability, durability, and firmness. This revolution in asphalt mixtures and widespread applications began in Great Britain.

The earliest forms of asphalt were built using a combination of stone, gravel, and various unearthed road-making materials. These early builders not only devised the first of many variant compositions of asphalt concrete, but also discovered ways to allow for proper water drainage and calculated the gradient and type of traffic that would travel on it to create firmer roads.

Asphalt’s American Debut

In the U.S., the first asphalt road was built in New Jersey in 1870 by Belgian chemist Edmund DeSmedt who had immigrated to the United States. His work would also lay the foundation for the paved roads on Pennsylvania Avenue in Washington, D.C. These early asphalt constructions were made with natural asphalt. The D.C. asphalt only lasted about eleven years before it began to deteriorate.

Since the primary sources of traffic were pedestrians and horse-drawn carriages, the use of stones and gravel overlaid by asphalt were sufficient for the time. It was not until the advent of the automobile that the weight and volume of traffic made these early stony asphalt mixtures obsolete. What followed was nearly a century of innovation and experimentation with different asphalt composite mixtures.

Innovations in Asphalt

Sand was one of the first additives combined with asphalt in the early iterations of modern day road pavement in the U.S. By the early 20th century, petroleum became the most widely used asphalt mixture over stones and natural asphalt. Though sand, water, and petroleum binding agents are still used to this day, many asphalt composite variations continued to increase durability and sustainability.

Today, the type of asphalt concrete that is used to build highways, buildings, and airport runways differs according to the weight of the traffic and the type of wear and tear that is anticipated. Some asphalt concrete is designed with mixtures that bear heavier loads, while others, such as highways, use variants of asphalt concrete that are more porous to allow for proper drainage. While concrete is used in some places to build firm walkways, most roads are made using asphalt concrete because it is less expensive, easier to maintain, and much more versatile than concrete is.

Paving companies, such as Dykes Paving in Atlanta, are continuing the long evolution of asphalt by devising innovative ways to improve the sustainability of asphalt concrete.

What Happens When Archaeological Discoveries Are Made During Road Work?

When artifacts or ruins are found during road work, usually the nearest archaeologists are contacted and asked to review what has been found. When there are few artifacts, they are set aside and saved for the coming archaeologists. But for a whole ruin or grave site (which does happen) roadwork could be stalled to make way for excavation.

Sometimes, road workers find a way to work around the ruin, so that archaeologists can excavate and do their work at the same time. Eventually though, road work does have to continue into the area, therefore archaeologists are work hard and excavate diligently.

Paving the Way for America

In 2005, road workers redoing part of U.S. route 80 in Bloomingdale, GA uncovered an old log road just four feet below the asphalt. This road is possibly dated all the way back to the Civil War or as late as the 1920s. Either way this road had a lot of history, as it is almost a hundred years old.

Some also might wonder what the big deal is about an old road, but think about it. These roads paved the way for modern day USA – literally paved! Without these roads, travel would have been more difficult in addition to the communication between towns and cities. At some point these roads were probably the only way to travel from town to town.

An Insight into Native American Culture

During road work in the U.S. last year, hundreds of Native American artifacts were found. One great find in St. George, UT is an ancient ruin that once belonged to the Shivwits tribe. There archaeologists found Anasazi pit houses, pottery, arrowheads, dinosaur fossils, and other tools they used for everyday life.

Uncovering a Roman-era Burial Site and Farmland

The U.K. has also had their share of roadwork artifacts. In the county of Yorkshire, road workers uncovered a Roman-era (possibly even before that) burial site. This burial site was over 2000 years old and had the only complete chariot ever found in the U.K. Despite the wear and tear on the chariot, archaeologists were able to use it and understand its functions.

In addition, within multiple areas around the U.K., road workers have uncovered pottery, farm tools, and various other items that describe life in the Roman-era farmland. The remains and bones found at various road work sites have told archaeologists about common causes of death during the era they came from and about ritualistic burial practices of the past.

You Never Know What History Will Be Found

The next time road work is happening in your area, tune into your local news or read your newspaper to see if anything has been discovered. You never know, as there could be history under the very ground you’re standing on!

The Series

Photographer Mike Mission’s new photo series, titled “Asphalt Archaeology” explores the recent archaeology of New York City through everyday objects found embedded in asphalt.

These photographs don’t show the ancient artifacts most people have come to expect from archaeological expeditions. Looking at Mission’s photo series, there are no mummies, bones, arrowheads, or broken pieces of pottery. Instead, there are bits of metal half embedded in the asphalt.

These urban artifacts are strange to see, strewn randomly on the street and completely without context. The objects that have been lost and eventually implanted in the asphalt of New York City are sometimes surprising. Among other things, Mission has photographed an entire padlock with nothing visibly broken about it, a long drill bit, and a set of keys. It’s an interesting testament to our fast-paced culture that people could lose these things and then walk over them day by day, until the pieces of metal have become part of the street around them.

Clues of the Past

This is urban archaeology–looking in cities to find clues about our past. By digging through-or under-more modern structures, urban archaeologists can reach the artifacts of people from previous centuries. This refuse can tell us a lot about how people in each city and neighborhood used to live. From food scraps to toys and furniture: What people were eating, buying, and using is telling of the lifestyle they had, and of their financial situation.

Looking Down

Unlike many urban archaeologists, Mission didn’t need to dig through New York’s streets in order to find artifacts-all he had to do was look down. Objects from the recent past can be found throughout the city’s streets, embedded in asphalt and forgotten.

The broken drill bit suggests a construction project, though there’s no way to tell if it was a personal project or a city sponsored job. The lost keys evoke the image of a hurried businessman, too rushed to realize that his keychain has fallen from his pocket. Mission’s photographs illustrate New York’s recent past by showing us how the people of the city are living.

This is a type of urban archaeology that can be practiced by anyone-photographer, archaeologist, or random passerby. Keep that in mind the next time you’re walking down an Atlanta street, be sure to look down. As Mike Mission has discovered, you never know what you’ll see.

The first asphalt was mixed as early as 1870 and laid by Belgian chemist Edmund J. Desmedt in front of City Hall in New Jersey. He also paved Pennsylvania Avenue in Washington, DC, right near the Capitol. The first mixture used sand, and the second was based on a more sophisticated mixture from Pitch Lake on the island of Trinidad. Hardy and resilient, this latter mixture was used for many years. Shortly thereafter, the first Hot Mix Asphalt (HMA) company opened and filed patents in Brooklyn, New York.

In 1901, the first modern asphalt was developed and patented by Frederick J. Warren. By this time, many other people and companies were competing with each other over the latest patents for asphalt mixes. The competition allowed cities to require higher standards of effectiveness and safety for their mixes, including adding warranties, which bankrupted some companies but spurred quick improvements.

Bringing a New Recipe into the Mix

The latest recipes for asphalt included refined petroleum, which was smoother and easier to lay. Then, in 1908, Henry Ford introduced his motor vehicle breakthrough: the Model T car. This was the first relatively affordable motor vehicle, and as it was mass-produced, the demand for high-quality, durable roads grew exponentially across the US. It also spurred government involvement. “Get the farmers out of the mud!” became a national cry for advancement.

Congress responded by passing the Federal-Aid Road Act of 1916 and creating the Federal-Aid Highway Program to disperse funding for construction and improvements. The program took off after World War I, when the Federal Highway Act of 1921 was introduced, and technology improved our abilities to lay roads quickly and efficiently with mechanical mixers and spreaders.

During World War II, the need for paved roads became dire as the US Military required more and better runways for our Air Force. In 1956, Congress passed the Interstate Highways Act, as families moved away from cities and into the suburbs, where they needed better means of transportation. Under President Dwight D. Eisenhower, the interstate highway program finally took shape.

The US Department of Transportation was Born

By 1966, demand for roads and for proper legislation and governance prompted the formation of the US Department of Transportation. The Federal Highway Administration was one of the major offices in this department. This was also a time of increased environmental concerns, and asphalt actually became one of America’s most recycled materials.

Today we continue to improve our roads, asphalt mixtures, and application technologies to be safer and more efficient. The official name for our highway system is the Dwight D. Eisenhower National System of Interstate and Defense Highways. It’s a mouthful of a name, and one of the greatest and most influential technological advances in the history of our country.

Image source:  www.iowadot.gov/virtual_museum/artifacts/OriginLincolnHighway.html