For years, asphalt has been an important part of our daily life that we likely don’t think too much about. It has been widely utilized all over the globe – because of its smooth and durable feature. In the US, most roads are covered with asphalt pavement – usually made from asphalt, stone, sand, and gravel.
In this article, we will explore more about this material – how was it invented, what its uses are, and how did it impact our modern transportation system.
Asphalt used in ancient times
The use of asphalt can be traced back for thousands of years. Asphalt, also known as bitumen, was a natural resource – used in the early 500 B.C. for waterproofing ancient temple baths and water tanks.
Asphalt was also used in constructing the walls of Babylon – used as mortar between bricks, and acts as a waterproofing agent. Furthermore, the first recorded use of asphalt on creating roads was on 625 B.C. Asphalt covered roads was used in ancient Babylon to make travels easier.
Asphalt was used on roads
In the early times, asphalt was only being used for similar purposes – Usually, for waterproofing. Up until the 18th century when an Englishman named John Metcalf, built 180 miles of asphalt roads in Yorkshire. This act was followed by Thomas Telford in the early 1800’s – where he built more than 900 miles of roads in Scotland.
After these milestones, John Loudon McAdam adopted the same idea – and created his better version of asphalt pavements. The method used by McAdam consists of stones and asphalt. The final product of this method is called “tarmacadam” pavements – and is still being used today.
Asphalt came to America
In 1870, the modern road asphalt was invented by a Belgium chemist, Edward J. de Smedt.
De Smedt, a college professor in Columbia University, made his own design of road asphalt – which he calls “sheet asphalt pavements”. He later used his design to pave Pennsylvania Avenue in Washington – where he used fifty four thousand square yards of sheet asphalt. One year after the accomplishment of De Smedt – a guy named Nathan B Abbot, filed the first patent for manufacturing hot mix asphalt.
Many ideas followed, and different scientists contributed to the improvement of asphalt technology – One of them is Frederick J. Warren. In 1900, Warren patented the “Bitulithic” pavement. The mixture consisted of bitumen and aggregate.
Modernization of asphalt
The demand for asphalt increased – and as a respond to this demand, scientist developed a way to improve the production of asphalt.
In 1907, asphalt from refined petroleum was introduced – and has been widely used over natural asphalt.
As the production of asphalt rises, different technologies were invented to further improve the process. In 1910, the first drum mixer and drum dryer-mixers were invented and came into use. In 1920, came the improvement of cold feed systems for portable and semi-portable systems. Then, in the 1930’s, vibrating screens and pressure injection systems were made.
In 1942, during World War II, asphalt technology greatly improved – because of the need of better surface for the heavy loads of military aircraft and cargo
The advancement of asphalt technology lead to the formation of The National Bituminous Concrete Association in 1955. Its main purpose it to improve the overall quality of asphalt technology – thru intensive research and lab testing. Then the following year, the Interstate Highways Act was passed – allotting fifty one billion dollars for road construction.
In 1986, The National Center for Asphalt Technology (NCAT) was established. In partnership between Auburn University and the National Asphalt Pavement Association (NAPA), these major group of scientist and engineers provide quality research and development to further improve the highway infrastructure in the US.
Present-day asphalt technology
Today, there’s an estimated 2.3 million miles of paved road in the US alone – in which 90% is paved with asphalt. In a global scale, the modern use of asphalt is approximately 102 million tonnes per year – where 85% of this asphalt is used as pavement binders. Furthermore, engineers and scientist developed a way to recycle asphalt pavement – creating new asphalt roads. The reclaimed asphalt pavement (RAP) is produced by removing asphalt and aggregates in a pavement. This is now then used in reconstructing roads – or other purposes like filling landfills, resurfacing, and acting as a base layer. For the record, asphalt pavement is the most recycled material in America for a long time. It is estimated that 90 million tonnes of asphalt is recycled each year. Doing this, offers to save great amount of money in reconstructing roads – while having the same quality and efficiency as the ordinary asphalt pavement.
Through the years, asphalt has been a part of the advancement of our infrastructures. From the ancient times up to our modern world, asphalt was widely used. The progress in the improvement of asphalt just shows how many people were dedicated in studying, researching, and developing this technology. Now, we can just enjoy the smooth, durable, and safe roads – thanks to asphalt.