Hello, my name is Gilles Gauthier. I'm responsible for the technical coordination and product development at TOTAL Bitumen. I will now talk to you about two alternatives to bitumen in the road construction industry: tar and cement. Let's start with tar. There's often a lot of confusion in the public's mind between bitumen and tar. Yet they're completely different materials. As you know it by now, bitumen is obtained from the distillation of crude oil. It is a petroleum product. On the other hand, tar is obtained from the combustion of coal in specific conditions of temperature and without oxygen. In these conditions, molecules of coal recombine into various hydrocarbon compounds. The heavier fraction is a black and sticky residue called tar. The mechanical properties of tar are very close to those of bitumen. It has been used as a binder in road construction for decades, just like bitumen. For certain properties like fuel resistance, or adhesion, tar is even superior to bitumen. However, tar is extremely different from bitumen in terms of chemical composition. The combustion of coal without oxygen induces the formation of specific molecules called polycyclic Aromatic Hydrocarbons or PAHs. PAHs are now well known to be carcinogenic. And they can represent up to 20 to 30% in the composition of tar. Now you understand why the use of tar in roads has been banned in most regions in the world... PAHs are also present in bitumen in extremely small quantities. At this level they are not considered harmful. In 2011, the International Agency for Research on Cancer, or IARC, reviewed all the studies made on bitumen in the last decades. The conclusion was that no evidence of any link between the exposition to bitumen and the formation of cancer could be established. Bitumen and tar are truly different indeed, and now you can help your family and friends to make the difference. Now, lets talk about another material that is used to build roads: cement. Cement is made out of crushed limestone. It is used as a binder, just like bitumen. If you mix cement with water and aggregates, you obtain a material called cement concrete. Concrete is commonly used to build houses, buildings...But it can also be used to build roads. For this application it competes directly with bitumen. But how do these materials compare in terms of performance? In fact, the technical choice between bitumen and concrete depends in which country you are. In most countries, like France or England, roads are constructed exclusively with bituminous materials. But in other countries, like Austria, almost all roads are concrete roads. In other places like the USA or Germany both techniques coexist. Generally speaking bitumen is more commonly used than concrete to build roads. And especially to make the very surface of the pavement, called the wearing course. Bitumen does have a lot of technical advantages over concrete. For example, the first is driving comfort: Concrete pavements have very stiff and sensitive to cracking. Transversal joints need to be cut to limit this cracking. And frankly it is not comfortable to drive on those. On the other hand, bituminous pavements are smooth and flexible so it feels much more comfortable driving on bitumen. The second advantage is noise: The stiffness of concrete pavement makes them very noisy, where the viscosity of bitumen has a damping effect that reduces noise. And it is also possible to formulate special asphalt mixes that are porous to make the pavement even quieter. The third advantage is the overall life cycle cost. Concrete pavements are slightly more expensive to construct. then, they generally do not require any maintenance for a very long time. But even that is not necessarily a good thing because when it eventually fails, it must be fully demolished and reconstructed from scratch, which is obviously very costly. On the other hand, asphalt pavements can be maintained and upgraded more easily all along its service life. Concrete pavement are also sensitive to underdesign, meaning that if the thickness of a concrete pavement is only slightly less than it was designed to be, the pavement will fail prematurely. The last argument is environmental. The making of a concrete road consumes more energy and releases more CO2 to the atmosphere than the construction of a bituminous pavement. Especially when you consider that asphalt pavements can be 100% recycled. To conclude this video, let me summary the essentials that you have to remember: Coal tar is made from coal, but it is hazardous and it is forbidden in more and more countries. Cement is made from limestone, it is used to build rigid structures and is bitumen's main competitor. Bitumen is made from petroleum, and is used to make flexible, easy maintenance roads. Thank you for your attention.