[MUSIC] Dear participant, hello. It's a pleasure to meet you again for this new technical session. I'm from IFSTAR, I already presented the video on surface treatment. In this video, I will present the most common test applied to asphalt mix and perform at the laboratory. This video presents the main formulation test for hot mixed asphalt carried out in laboratory. This test allow for a variation of varied behavior in contoured standardized condition in relation with the ground stresses allowing for either the optimization, the composition during formulation study, or for verification and assessment often [INAUDIBLE] to deterioration. The test presented are the European tests and in particular those used in France. In the USA the method are comparable but the test are somewhat different, particularly for behaviors linked to thermal static. The French method of the formulation of asphalt mixes in a laboratory has been in development for more than 30 years now to satisfy the of the pavement sickness design method and to confirm the properties at work sites. This test allowed for the characterization of behaviors, measurement of mechanical performances and aberration of resistances of stresses on the pavement. There are both simulation tests such as resistance to sweeping by water, and resistance to rotting by flow of asphalt mixes and more fundamental test. To measure intrinsic properties such as complex [INAUDIBLE] or [INAUDIBLE] resistance of asphalt mixes. Before studying the behavior of material in place, it is necessary to make sure that it can be applied properly at the work site. The gyratory compactor test combines vertical compression Is a single action jack and rotation with an angle of inclination of 1 degree in France and 1.25 degree in the USA. The axis of a cylinder of given dimension at the mixture manufactory temperature. This effects simulate the needing of shearing of grains of asphalt mixings during compacting. There is a correspondence with percentage of void verify at work site. Percentage work site void equal percentage of a theory sheer compactor void for a number of gyration equal to the sickness of the expressed in millimeter. For example, the person does a void of a makes a 40 millimeter sickness with a other workside, void content close to that in laboratory after 40 gyration. The suitability for compacting is evaluated. The formulation is adjusted to bring it into compliance with a product standard. This is a central test of asphalt mix composition studies and it is one for which the behavior are verified. The sensitivity to stripping by water involves comparing the resistancies to compression of a batch of pieces, five to six in general, immersed and saturated in water at a given temperature, generally 18 degrees, but also 14 degrees. With pieces conserved in air foditamine duration generally seven days but also four days. The higher the ratio, the better the resistance of stripping. A ratio of 80% is often considered to be a good result. The test pieces are generate prepared in laboratory by double effects static compaction of dimension adapted to the maximum size. They can also be called there at the job site. The resistance to writing by crate. And there are a general load and at the highest temperature is simulated by your well written test. Which involved monitoring the deformation produced by the passing of a wheel on a platter kept on a mold of [INAUDIBLE] dimension. And as function of a sickness of the layer five or ten centimeter. Temperature in the plate is maintained constant at 60 degree plus or minus 2 degree. The rut at measure for a number of paces of 3,000, 10,000, and 30,000 cycle according to the specification. The deformation is expressed in rut. Deformation measure compared with the thickness of the plate, and generally lays down the threshold of 7.5 and 20 to find the European specification of asphalt product performance classes. The viscoelastic behavior of asphalt mix is governed by the nature of asphalt. The rigidity of the [INAUDIBLE] is a function of its temperature and the speed of loading. These two parameter must be controlled in order to measure the complex [INAUDIBLE] of the asphalt mix. It includes an elastic pot and a viscous pot. This is a discrepancy called the Phase Angle between the mechanical stress and deformation resistance of the asphalt mix. As a reminder this notion was presented to you during the eulogy called characteristic test of asphalt in the previous video. The model test are done in a domain of small deformation. 50 micro informations to avoid fatigue image. The and trapezoidal test pieces of standardized dimensions are subjected to a 2 point bending test embed at the base and subjected to a sinusoidal bending at the top with different frequency one to 30 else. And temperature generated when minus ten and 40 degrees. Other types of mechanical stresses can be applied such as three or four point bending on bars, compression traction, or shearing on cylinders. So modulus results can be expressed in various forms. Pavement design modulus, for example, are 15 degrees and ten hertz. Master curves, black curves, Cole-Cole plane. The resistance to fatigue characterize the damage in the large deformation causing by the mechanical disruption cracks in the materials. The greater the stress, the lesser the resistance of a time. The simulates the bending with each pass of axle. The principle of the test is the same as for the modulus test. Two point bending on trapezoidal test piece, but for one single temperature, ten degrees, and one single frequency, 25 hertz, according to three high label of information, at about 80 to 140 and with six repetitions per level. The fatigue line is determined by double the linear regression and the epsilon 6 fatigue dimension criterion is calculated. It is a deformation leading to breakage at one million cycles. The [INAUDIBLE] the [INAUDIBLE] behavior which increases a walking life of the courses for the [INAUDIBLE] level of stresses or reduce the sickness for equivalent duration. Observe [INAUDIBLE] your test such as resistant to thermal cracks by [INAUDIBLE] shrinkage test or test for [INAUDIBLE] bounding strength can be carried out within the frameworks on the formulation steadies. Both of asphalt mixtures are standardized for these various tests. The formulation study involves carrying out these various tests in the laboratory to confirm the composition of the asphalt mix. Net share and dozing of it's constituents aggregants and asphalt counter. Thank you very much for your attention and see you for another section.
