International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 2, February- 2013 Emerging Trends in Greener Pavements Vignesh H*, Ramesh Babu N.G, Manivasagan V, Suganya S and Eajas Basha M Department of Biotechnology, Adhiyamaan College of Engineering (Autonomous), Hosur-635109, Tamil Nadu, India *Corresponding Author Vignesh H DepartmentIJERT of Biotechnology, Adhiyamaan CollegeIJERT of Engineering (Autonomous), Hosur-635109, Tamil Nadu, India www.ijert.org 1 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 2, February- 2013 Abstract 1. Introduction The traditional, commercial and the The traditional, commercial most commonly used method for and the most commonly used method paving roads and pavements is for paving roads and pavements is asphalting. Asphalt also known as asphalting. Due to its adverse effects bitumen is a sticky, black and highly and increase in the rate of global viscous liquid or semi-solid form of warming, finding a newer method petroleum entirely soluble in carbon was mandatory. The green revolution disulfide, and composed primarily of paved the way to overcome those highly condensed polycyclic adverse effects by the usage of aromatic hydrocarbons. It contains renewable resources and wastes. This toxic, heavy metals including nickel, biologically modified form of lead, mercury, vanadium, chromium, Asphalt is called BioAsphalt. In this mercury, arsenic and selenium. review, the effects of traditional Oxidation can cause deterioration pavements, their properties and how via long-term aging and eventually to overcome those effects by using result in cracking of asphalt eco-friendly methods have been pavements. Due to the adverse discussed. effects of asphalting, greener method was mandatory. Today’s ‘green 2. Asphalt revolution’ has brought about an interesting and more environmentally Asphalt i/ˈæsfɔːlt/ or friendly alternative to asphalt known /ˈæʃfɔːlt/ or /ˈæsʃfɛlt/, also known as as ‘BioAsphalt’ which is free from bitumen, is a sticky, black and highly toxic materials. Bioasphalt is IJERTanIJERT viscous liquid or semi-solid form of asphalt alternative made from petroleum entirely soluble in carbon bitumen from non-petroleum based disulfide, and composed primarily of renewable resources. Bioasphalting highly condensed polycyclic decreases paving costs by 20%, aromatic hydrocarbons. It may be decreases carbon footprint, found in natural deposits or may be a diminishes greenhouse gas refined product; it is a substance emissions, and it boasts increased classed as a pitch. Until the 20th pavement life. century, the term asphaltum was also used [4]. Keywords: asphalt, green revolution, bioasphalt www.ijert.org 2 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 2, February- 2013 Figure 1. Asphalt but usually made by the distillation of crude oil. Naturally occurring asphalt/bitumen is sometimes specified by the term "crude bitumen"; its viscosity is similar to that of cold molasses. [1] [25] whilst the material obtained from the fractional distillation of crude oil [boiling at 525 °C (977 °F)] is sometimes referred to as "refined The primary use of bitumen". asphalt/bitumen is in road construction, where it is used as the 3. Sources glue or binder mixed with aggregate particles to create asphalt concrete. Natural deposits of Its other main uses are for asphalt/bitumen include lakes such bituminous waterproofing products, as the Pitch Lake in Trinidad and including production of roofing felt Tobago and Lake Bermudez in and for sealing flat roofs. Venezuela, Gilsonite, the Dead Sea, asphalt/bitumen-impregnated The terms asphalt and sandstones known as bituminous bitumen are often used rock and the similar "tar sands". interchangeably to mean both naturalIJERTIJERT Asphalt/bitumen was mined at and manufactured forms of the Ritchie Mines in Macfarlan in substance. In American English, Ritchie County, West Virginia in the asphalt (or asphalt cement) is the United States from 1852 to 1873. carefully refined residue from the distillation process of selected crude Asphalt/bitumen can be oils. Outside the United States, the separated from the other components product is often called bitumen. The in crude oil (such as naphtha, term Bitumen is preferred in geology. gasoline and diesel) by the process of Common usage often refers to fractional distillation, usually under various forms of asphalt/bitumen as vacuum conditions. A better "tar", such as at the La Brea Tar Pits. separation can be achieved by further Another term, mostly archaic, refers processing of the heavier fractions of to asphalt/bitumen as "pitch". The the crude oil in a de-asphalting unit, pitch used in this mixture is which uses either propane or butane sometimes found in natural deposits in a supercritical phase to dissolve the lighter molecules which are then www.ijert.org 3 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 2, February- 2013 separated. Further processing is because the number of molecules possible by "blowing" the product: with different chemical structures is namely reacting the product with extremely large" [21]. oxygen. This makes the product harder and more viscous. Asphalt/bitumen is typically stored and transported at Naturally occurring deposits temperatures around 150°C (300°F). of asphalt/bitumen are formed from Sometimes diesel oil or kerosene are the remains of ancient, microscopic mixed in before shipping to retain algae (diatoms) and other ancient liquidity; upon delivery, these lighter living beings. These remains were materials are separated out of the deposited in the mud on the bottom mixture. This mixture is often called of the ocean or lake where the "bitumen feedstock", or BFS. organisms lived. Due to the heat (above 50 °C) and pressure of being 5. Components buried deep in the earth, the remains were transformed into materials such Most natural bitumens as asphalt/bitumen, kerogen, or contain sulfur and several heavy petroleum. Deposits at the La Brea metals, such as nickel, vanadium, Tar Pits is an example. lead, chromium, mercury, arsenic, selenium, and other toxic elements. 4. Properties Bitumens can provide good preservation of plants and animal The substance is completely fossils. soluble in carbon disulfide, and composed primarily of a mixture IJERTof 6. Usage highly condensed polycyclicIJERT aromatic hydrocarbons; it is most a) Earlier commonly modelled as a colloid, The Greek fire, whose with asphaltenes as the dispersed composition was a military secret of phase and maltenes as the continuous the Byzantine navy, contained phase (though there is some asphalt/bitumen as a component disagreement amongst chemists among other things. regarding its structure). One report stated although a "considerable Among the earlier uses of amount of work has been done on the asphalt/bitumen in the United composition of asphalt, it is Kingdom was for etching. William exceedingly difficult to separate Salmon's Polygraphice (1673) individual hydrocarbon in pure provides a recipe for varnish used in form", [21] and "it is almost etching, consisting of three ounces of impossible to separate and identify virgin wax, two ounces of mastic, all the different molecules of asphalt, and one ounce of asphaltum [22]. By www.ijert.org 4 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 2, February- 2013 the time of the fifth edition in 1685, asphalt/bitumen and typically less he had included more asphaltum than 1.5% chemical additives. recipes from other sources [23]. Asphalt/bitumen is used to The Tongva, Luiseño and make Japan black, a lacquer known Chumash, people collected the especially for its use on iron and naturally occurring asphalt/bitumen steel. that seeped to the surface above underlying petroleum deposits. All 7. Environmental impacts of three used the substance as an Asphalt pavement adhesive. It was also used in decorations. Unhealthy fumes Odors b) Modern Fossil fuels The largest use of asphalt/bitumen is for making Contains toxic, heavy asphalt concrete for road surfaces metals including nickel, and accounts for approximately 85% lead, mercury, vanadium, of the asphalt consumed in the chromium, mercury, arsenic United States. Asphalt concrete and selenium. pavement material is commonly Oxidation can cause composed of 5% asphalt/bitumen deterioration via long-term cement and 95% aggregates (stone, aging and eventually result sand, and gravel). in cracking. Mastic asphalt is a type IJERTofIJERT 8. Green Revolution asphalt which differs from dense In the recent past, there‟s a graded asphalt (asphalt concrete) in lot of movement and thinking when that it has a higher asphalt/bitumen it comes to creating more (binder) content, usually around 7– environmentally friendly and 10% of the whole aggregate mix, as sustainable products. They‟re often opposed to rolled asphalt concrete, derived from organic components, or which has only around 5% added even waste by-products. Today‟s asphalt/bitumen. „green revolution‟ has brought about Mixing asphalt with an interesting and more petroleum solvents forms "cutbacks" environmentally friendly alternative with reduced melting point, or to Asphalt known as „BioAsphalt‟ mixtures with water to turn the which is free from toxic materials. asphalt/bitumen into an emulsion. Bio-oil could potentially serve as an Asphalt emulsions contain up to 70% antioxidant additive