Asphalt ( ˈæs.fɒlt (help·info)) is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits sometimes termed asphaltum.[1] It is most commonly modelled as a colloid, with asphaltenes as the dispersed phase and maltenes as the continuous phase (though there is some disagreement amongst chemists regarding its structure).[citation needed] One writer states that although a "considerable amount of work has been done on the composition of asphalt, it is exceedingly difficult to separate individual hydrocarbon in pure form",[2] and "it is almost impossible to separate and identify all the different molecules of asphalt, because the number of molecules with different chemical structure is extremely large".[3]
In U.S. and Polish terminology, asphalt (or asphalt cement) is the carefully refined residue from the distillation process of selected crude oils. Outside these countries, the product is often called bitumen. Natural deposits terminology also sometimes uses the word bitumin, such as at the La Brea Tar Pits.
The primary use of asphalt is in road construction, where it is used as the glue or binder for the aggregate particles. The road surfacing material is usually called 'asphaltic concrete', AC in North America, or 'asphalt' elsewhere.
In U.S. and Polish terminology, asphalt (or asphalt cement) is the carefully refined residue from the distillation process of selected crude oils. Outside these countries, the product is often called bitumen. Natural deposits terminology also sometimes uses the word bitumin, such as at the La Brea Tar Pits.
The primary use of asphalt is in road construction, where it is used as the glue or binder for the aggregate particles. The road surfacing material is usually called 'asphaltic concrete', AC in North America, or 'asphalt' elsewhere.
Background
Ancient times
In the ancient Middle East, natural asphalt deposits were used for mortar between bricks and stones, to cement parts of carvings such as eyes into place, for ship caulking, and for waterproofing.[1] The Persian word for asphalt is mumiya, which is related to the English word mummy. Asphalt was also used by ancient Egyptians to embalm mummies.[1][8] In the ancient Far East, natural asphalt was slowly boiled to get rid of the higher fractions, leaving a material of higher molecular weight which is thermoplastic and when layered on objects, became quite hard upon cooling. This was used to cover objects that needed waterproofing,[1] such as scabbards and other items. Statuettes of household deities were also cast with this type of material in Japan, and probably also in China.[citation needed]
In North America, archaeological recovery has indicated that asphaltum was sometimes used to apply stone projectile points to a wooden shaft.[9]
Early use in Europe
Bituminous outcrop of the Puy de la Poix, Clermont-Ferrand, France
An 1838 edition of Mechanics Magazine cites an early use of asphalt in France. A pamphlet dated 1621, by "a certain Monsieur d'Eyrinys, states that he had discovered the existence (of asphaltum) in large quantities in the vicinity of Neufchatel", and that he proposed to use it in a variety of ways - "principally in the construction of air-proof granaries, and in protecting, by means of the arches, the water-courses in the city of Paris from the intrusin of dirt and filth", which at that time made the water unusable. "He expatiates also on the excellence of this material for forming level and durable terraces" in palaces, "the notion of forming such terraces in the streets not one likely to cross the brain of a Parisian of that generation".[10] But it was generally neglected in France until the revolution of 1830. Then, in the 1830s, there was a surge of interest, and asphalt became widely used "for pavements, flat roofs, and the lining of cisterns, and in England, some use of it had been made of it for similar purposes". Its rise in Europe was "a sudden phenomenon", after natural deposits were found "in France at Osbann (BasRhin), the Parc (l'Ain) and the Puy-de-la-Poix (Puy-de-Dome)", although it could also be made artificially.[11] One of the earliest uses in France was the laying of about 24,000 square yards of Seyssel asphalt at the Place de la Concorde in 1835.[12]
In the ancient Middle East, natural asphalt deposits were used for mortar between bricks and stones, to cement parts of carvings such as eyes into place, for ship caulking, and for waterproofing.[1] The Persian word for asphalt is mumiya, which is related to the English word mummy. Asphalt was also used by ancient Egyptians to embalm mummies.[1][8] In the ancient Far East, natural asphalt was slowly boiled to get rid of the higher fractions, leaving a material of higher molecular weight which is thermoplastic and when layered on objects, became quite hard upon cooling. This was used to cover objects that needed waterproofing,[1] such as scabbards and other items. Statuettes of household deities were also cast with this type of material in Japan, and probably also in China.[citation needed]
In North America, archaeological recovery has indicated that asphaltum was sometimes used to apply stone projectile points to a wooden shaft.[9]
Early use in Europe
Bituminous outcrop of the Puy de la Poix, Clermont-Ferrand, France
An 1838 edition of Mechanics Magazine cites an early use of asphalt in France. A pamphlet dated 1621, by "a certain Monsieur d'Eyrinys, states that he had discovered the existence (of asphaltum) in large quantities in the vicinity of Neufchatel", and that he proposed to use it in a variety of ways - "principally in the construction of air-proof granaries, and in protecting, by means of the arches, the water-courses in the city of Paris from the intrusin of dirt and filth", which at that time made the water unusable. "He expatiates also on the excellence of this material for forming level and durable terraces" in palaces, "the notion of forming such terraces in the streets not one likely to cross the brain of a Parisian of that generation".[10] But it was generally neglected in France until the revolution of 1830. Then, in the 1830s, there was a surge of interest, and asphalt became widely used "for pavements, flat roofs, and the lining of cisterns, and in England, some use of it had been made of it for similar purposes". Its rise in Europe was "a sudden phenomenon", after natural deposits were found "in France at Osbann (BasRhin), the Parc (l'Ain) and the Puy-de-la-Poix (Puy-de-Dome)", although it could also be made artificially.[11] One of the earliest uses in France was the laying of about 24,000 square yards of Seyssel asphalt at the Place de la Concorde in 1835.[12]
Early use in the United Kingdom
William Salmon's Polygraphice (1673) provides a recipe for varnish used in etching, consisting of three ounces of virgin wax, two ounces of mastic, and one ounce of asphaltum.[13]
In Britain, the first patent was 'Cassell's patent asphalte or bitumen' in 1834.[11] Then on 25 November 1837, Richard Tappin Claridge patented the use of Seyssel asphalt (patent #7849), for use in asphalte pavement,[14][15] having seen it employed in France and Belgium when visiting with Frederick Walter Simms, who worked with him on the introduction of asphalt to Britain.[16] Dr T. Lamb Phipson claims that his father, Samuel Ryland Phipson, a friend of Claridge, was also "instrumental in introducing the asphalte pavement (in 1836)".[17] Indeed, mastic pavements had been previously employed at Vauxhall by a competitor of Claridge, but without success.[12]
In 1838, Claridge obtained patents in Scotland on 27 March, and Ireland on 23 April, and in 1851 he sought to extend the duration of all three patents.[11][18][19][20] He formed Claridge's Patent Asphalte Company for the purpose of introducing to Britain "Asphalte in its natural state from the mine at Pyrimont Seysell in France",[21] and "laid one of the first asphalt pavements in Whitehall".[22] Trials were made of the pavement in 1838 on the footway in Whitehall, the stable at Knightsbridge Barracks,[21][23] "and subsequently on the space at the bottom of the steps leading from Waterloo Place to St. James Park".[23] "The formation in 1838 of Claridge's Patent Asphalte Company (with a distinguished list of aristocratic patrons, and Marc and Isambard Brunel as, respectively, a trustee and consulting engineer), gave an enormous impetus to the development of a British asphalt industry".[19] "By the end of 1838, at least two other companies, Robinson's and the Bastenne company, were in production",[24] with asphalt being laid as paving at Brighton, Herne Bay, Canterbury, Kensington, the Strand, and a large floor area in Bunhill-row, while meantime Claridge's Whitehall paving "continue(d) in good order".[25]
Indeed in 1838, there was a flurry of entrepreneurial activity over asphalt, which had uses beyond paving. For example, asphalt could also used for flooring, damp proofing in buildings, and for waterproofing of various types of pools and baths, with these latter themselves proliferating in the 1800s.[1][11][26] On the London stockmarket, there were various claims as to the exclusivity of asphalt quality from France, Germany and England. And numerous patents were granted in France, with similar numbers of patent applications being denied in England due to their similarity to each other. In England, "Claridge's was the type most used in the 1840s and 50s" [24]
In 1914, Claridge's Company entered into a joint venture to produce tar-bound macadam,[27] with materials manufactured through a subsidiary company called Clarmac Roads Ltd.[28] Two products resulted, namely Clarmac, and Clarphalte, with the former being manufactured by Clarmac Roads and the latter by Claridge's Patent Asphalte Co., although Clarmac was more widely used.[29][a] However, the First World War impacted financially on the Clarmac Company, which entered into liquidation in 1915.[30][31] The failure of Clarmac Roads Ltd had a flow-on effect to Claridge's Company, which was itself compulsorily wound up,[32] ceasing operations in 1917,[33][34] having invested a substantial amount of funds into the new venture, both at the outset,[32] and in a subsequent attempt to save the Clarmac Company.[30]
William Salmon's Polygraphice (1673) provides a recipe for varnish used in etching, consisting of three ounces of virgin wax, two ounces of mastic, and one ounce of asphaltum.[13]
In Britain, the first patent was 'Cassell's patent asphalte or bitumen' in 1834.[11] Then on 25 November 1837, Richard Tappin Claridge patented the use of Seyssel asphalt (patent #7849), for use in asphalte pavement,[14][15] having seen it employed in France and Belgium when visiting with Frederick Walter Simms, who worked with him on the introduction of asphalt to Britain.[16] Dr T. Lamb Phipson claims that his father, Samuel Ryland Phipson, a friend of Claridge, was also "instrumental in introducing the asphalte pavement (in 1836)".[17] Indeed, mastic pavements had been previously employed at Vauxhall by a competitor of Claridge, but without success.[12]
In 1838, Claridge obtained patents in Scotland on 27 March, and Ireland on 23 April, and in 1851 he sought to extend the duration of all three patents.[11][18][19][20] He formed Claridge's Patent Asphalte Company for the purpose of introducing to Britain "Asphalte in its natural state from the mine at Pyrimont Seysell in France",[21] and "laid one of the first asphalt pavements in Whitehall".[22] Trials were made of the pavement in 1838 on the footway in Whitehall, the stable at Knightsbridge Barracks,[21][23] "and subsequently on the space at the bottom of the steps leading from Waterloo Place to St. James Park".[23] "The formation in 1838 of Claridge's Patent Asphalte Company (with a distinguished list of aristocratic patrons, and Marc and Isambard Brunel as, respectively, a trustee and consulting engineer), gave an enormous impetus to the development of a British asphalt industry".[19] "By the end of 1838, at least two other companies, Robinson's and the Bastenne company, were in production",[24] with asphalt being laid as paving at Brighton, Herne Bay, Canterbury, Kensington, the Strand, and a large floor area in Bunhill-row, while meantime Claridge's Whitehall paving "continue(d) in good order".[25]
Indeed in 1838, there was a flurry of entrepreneurial activity over asphalt, which had uses beyond paving. For example, asphalt could also used for flooring, damp proofing in buildings, and for waterproofing of various types of pools and baths, with these latter themselves proliferating in the 1800s.[1][11][26] On the London stockmarket, there were various claims as to the exclusivity of asphalt quality from France, Germany and England. And numerous patents were granted in France, with similar numbers of patent applications being denied in England due to their similarity to each other. In England, "Claridge's was the type most used in the 1840s and 50s" [24]
In 1914, Claridge's Company entered into a joint venture to produce tar-bound macadam,[27] with materials manufactured through a subsidiary company called Clarmac Roads Ltd.[28] Two products resulted, namely Clarmac, and Clarphalte, with the former being manufactured by Clarmac Roads and the latter by Claridge's Patent Asphalte Co., although Clarmac was more widely used.[29][a] However, the First World War impacted financially on the Clarmac Company, which entered into liquidation in 1915.[30][31] The failure of Clarmac Roads Ltd had a flow-on effect to Claridge's Company, which was itself compulsorily wound up,[32] ceasing operations in 1917,[33][34] having invested a substantial amount of funds into the new venture, both at the outset,[32] and in a subsequent attempt to save the Clarmac Company.[30]
Early use in the United States
The first use of asphaltum in the New World was by indigenous Indian tribes. On the west coast, as early as the 1200s, the Tongva and Chumash Nations collected the naturally occurring asphaltum that seeped to the surface above underlying petroleum deposits. Both tribes used the substance as an adhesive. It is found on many different artifacts of tools and ceremonial items. For example, it was used on rattles to adhere gourds or turtle shells to rattle handles. It was also used in decorations. Small round shell beads were often set in asphatum to provide decorations. It was used as a sealant on baskets to make them water tight for carrying water. Asphaltum was used also to seal the planks on ocean-going canoes.
Roads in the US have been paved with asphalt since at least 1870, when a street in front of Newark, NJ's City Hall was paved. In 1876, asphalt was used to pave Pennsylvania Avenue in Washington, DC, in time for the celebration of the national centennial.[35] Asphalt was also used for flooring, paving and waterproofing of baths and swimming pools during the early 1900s, following similar trends in Europe.[26]
The first use of asphaltum in the New World was by indigenous Indian tribes. On the west coast, as early as the 1200s, the Tongva and Chumash Nations collected the naturally occurring asphaltum that seeped to the surface above underlying petroleum deposits. Both tribes used the substance as an adhesive. It is found on many different artifacts of tools and ceremonial items. For example, it was used on rattles to adhere gourds or turtle shells to rattle handles. It was also used in decorations. Small round shell beads were often set in asphatum to provide decorations. It was used as a sealant on baskets to make them water tight for carrying water. Asphaltum was used also to seal the planks on ocean-going canoes.
Roads in the US have been paved with asphalt since at least 1870, when a street in front of Newark, NJ's City Hall was paved. In 1876, asphalt was used to pave Pennsylvania Avenue in Washington, DC, in time for the celebration of the national centennial.[35] Asphalt was also used for flooring, paving and waterproofing of baths and swimming pools during the early 1900s, following similar trends in Europe.[26]
Rolled asphalt concrete
The largest use of asphalt is for making asphalt concrete for road surfaces and accounts for approximately 85% of the asphalt consumed in the United States. Asphalt pavement material is commonly composed of 5 percent asphalt cement and 95 percent aggregates (stone, sand, and gravel). Due to its highly viscous nature, asphalt cement must be heated so that it can be mixed with the aggregates at the asphalt mixing plant. There are about 4,000 asphalt mixing plants in the U.S.
Asphalt road surface is the most widely recycled material in the US, both by gross tonnage and by percentage. According to a report issued by the Federal Highway Administration and the United States Environmental Protection Agency, 80% of the asphalt removed each year from road surfaces during widening and resurfacing projects is reused as part of new roads, roadbeds, shoulders and embankments.
Roofing shingles account for most of the remaining asphalt consumption. Other uses include cattle sprays, fence post treatments, and waterproofing for fabrics.
Asphalt is widely used in airports around the world. Due to the sturdiness, it is widely used for runways dedicated to aircraft landing and taking off.
The largest use of asphalt is for making asphalt concrete for road surfaces and accounts for approximately 85% of the asphalt consumed in the United States. Asphalt pavement material is commonly composed of 5 percent asphalt cement and 95 percent aggregates (stone, sand, and gravel). Due to its highly viscous nature, asphalt cement must be heated so that it can be mixed with the aggregates at the asphalt mixing plant. There are about 4,000 asphalt mixing plants in the U.S.
Asphalt road surface is the most widely recycled material in the US, both by gross tonnage and by percentage. According to a report issued by the Federal Highway Administration and the United States Environmental Protection Agency, 80% of the asphalt removed each year from road surfaces during widening and resurfacing projects is reused as part of new roads, roadbeds, shoulders and embankments.
Roofing shingles account for most of the remaining asphalt consumption. Other uses include cattle sprays, fence post treatments, and waterproofing for fabrics.
Asphalt is widely used in airports around the world. Due to the sturdiness, it is widely used for runways dedicated to aircraft landing and taking off.
Mastic asphalt
Mastic asphalt is a type of asphalt which differs from dense graded asphalt (asphalt concrete) in that it has a higher bitumen (binder) content, usually around 7–10% of the whole aggregate mix, as opposed to rolled asphalt, which has only around 5% added bitumen. This thermoplastic substance is widely used in the building industry for waterproofing flat roofs and tanking underground. Mastic asphalt is heated to a temperature of 210 °C (410 °F) and is spread in layers to form an impervious barrier about 20 millimeters (0.8 in) thick.
Mastic asphalt is a type of asphalt which differs from dense graded asphalt (asphalt concrete) in that it has a higher bitumen (binder) content, usually around 7–10% of the whole aggregate mix, as opposed to rolled asphalt, which has only around 5% added bitumen. This thermoplastic substance is widely used in the building industry for waterproofing flat roofs and tanking underground. Mastic asphalt is heated to a temperature of 210 °C (410 °F) and is spread in layers to form an impervious barrier about 20 millimeters (0.8 in) thick.
Asphalt emulsion
A number of technologies allow asphalt to be mixed at much lower temperatures. These involve mixing the asphalt with petroleum solvents to form "cutbacks" with reduced melting point or mixtures with water to turn the asphalt into an emulsion. Asphalt emulsions contain up to 70% asphalt and typically less than 1.5% chemical additives. There are two main types of emulsions with different affinity for aggregates, cationic and anionic. Asphalt emulsions are used in a wide variety of applications. Chipseal involves spraying the road surface with asphalt emulsion followed by a layer of crushed rock or gravel. Slurry Seal involves the creation of a mixture of asphalt emulsion and fine crushed aggregate that is spread on the surface of a road. Cold mixed asphalt can also be made from asphalt emulsion to create pavements similar to hot-mixed asphalt, several inches in depth and asphalt
A number of technologies allow asphalt to be mixed at much lower temperatures. These involve mixing the asphalt with petroleum solvents to form "cutbacks" with reduced melting point or mixtures with water to turn the asphalt into an emulsion. Asphalt emulsions contain up to 70% asphalt and typically less than 1.5% chemical additives. There are two main types of emulsions with different affinity for aggregates, cationic and anionic. Asphalt emulsions are used in a wide variety of applications. Chipseal involves spraying the road surface with asphalt emulsion followed by a layer of crushed rock or gravel. Slurry Seal involves the creation of a mixture of asphalt emulsion and fine crushed aggregate that is spread on the surface of a road. Cold mixed asphalt can also be made from asphalt emulsion to create pavements similar to hot-mixed asphalt, several inches in depth and asphalt
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