[MUSIC] Dear participants, hello. It's my pleasure to meet you again in this technical session. Today we'll present some modifications of the bitumen and why they are used. We have seen in the previous video, presented by Jill Gotye, that it's possible to modify the bitumen's characteristics. The addition of polymer is a one polymer modification of the bitumen. In this video I will focus on the modification of bitumen with crumb rubber And on the additivation of bitumen to decrease the working temperature. First, I will present the modification with crumb rubber. Bitumen is a viscoelastic material with suitable properties for paving and roofing applications. However, with the increased traffic volumes and vehicles loads, there is a need to improve conventional bitumen properties especially the resistance to permanent deformation and the resistance to cracking. The [INAUDIBLE] is s-polymers are the commonly used polymers to improve the elasticity in the cohesion of the vitamin. The substitution of this virgin polymers by recycled polymers has been taken into consideration. In order to reduce the modification cost and obtain environmental benefits. Thus particles of crumb rubber made with recycled bits of tires can be used in the polymer to increase its elastic properties and cohesion. Bitumens modified with crumb rubber are usually called CRMB. Crumb Rubber Modified Bitumen, the CRMBs are cheaper alternative to PMBs. For example, India is a significant user of CRMB. To manufacture CRMB, fine crumb rubber is added and dispersed in the bitumen Using your high share blender. Your tense CRMB may contain up to 25 percent of crumb rubber and display enhanced performances, which may be seen as up to 1.5 percent of the asphalt mixture. The CRMB's are well known to be not very stable during the storage at high temperature. In Europe there is no specific standard for CRMB. In fact, the use of that product falls under EN 14023, framework specification for polymer modified bitumen. The crumb rubber can also be incorporated directly into the mixed plant. What aggregates filler and sand. The warm mix asphalts are a relatively recent technique developed in response to the needs of the road industry for decreasing energy consumptions and emissions and worker's exposure. In France, for example, the French world companies signed in March 2009 an agreement of voluntary commitment with the Ministry of Ecology, Energy, Sustainable Development in the town and country planning. In which they make in particular a commitment to reduce greenhouse gas emissions of the order of 33% to the recent in 2020, leading to use of warm mix asphalts. There are two main ways to manufacture warm mixes. First is the bitumen foam and a course solution is injected in the hot bitumen. Just before the mixing with the aggregates at warm temperature about 120 degrees celsius, 140 degrees celsius the bitumen expansion, due to the water expansion, improves the uncoating of the aggregates at lower temperature. The second one is the additivation of the bitumen with specific additives. This additivation aims at getting the same workability of the asphalt mix at lower temperature. Studies carried out in Europe and in the United States show that these techniques to indeed did a lot to reduce the energy consumption up to 35% and to reduce CO2 emissions up to 40% Moreover workers operating improved working conditions with less exposure to fumes. There are other benefits which are not environmental or safety and health oriented, but would direct added value for the customer's business. Lower temperature means, Quicker cooling and so allows opening the traffic earlier, applying several layers in a row and even extension of the working seasons. In conclusion, chrome rubber can be added to the bitumen to enhance the properties of the mix like resistant to permanent deformation and resistance to cracking. CRMB is a cheap alternative to PMBs, but it's not so stable during a storage at high temperature as PMBs are. Warm mix asphalt can be manufactured using bitumen foam or bitumen additive rated with specific additives. This technique allows reducing the energy consumption and the emissions and improving the workers comfort on the job site. Thanks for your attention. [MUSIC]