[MUSIC] Dear participants, hello, my name is Laurence Lapalu. I am a senior research engineer at the Total Research Center of Solaize in France. My research and development programs are 100% dedicated to bitumen. And I am very glad to have this opportunity to share with you my knowledge. On this very special and very unique product. Now that you are familiar with the composition of the bitumen and its main characteristics. We are going to look together at the main standard test. Which can be carried to measure or assess the consistency of the bitumen. In this video, we will explore what are the two main characterization tests. The penetration and the ring and ball softening point. First, the penetration test characterized the consistency of bitumen. Its hardness and stiffness at ambient temperature. Then we will have a look at the softening point test. During which, bitumen changes from solid state to liquid state. Let's start with the testing of penetration. In the European specifications, a road building bitumen is graded. According to the results of a penetration test method. The penetration test is a a standardized test. In the Europe the standard reference is EN 1426. In this test, a standard loaded needle penetrates a sample of bitumen. Under specified test conditions. A temperature around ambient, usually 25 degrees celsius. A load of 100 grams is applied for 5 second on 25 degrees celsius. The depths to which the meter penetrates the surface of bitumen is measured. So, the less the needle penetrates, the harder the bitumen is. You now understand, that the result of this test will characterize the hardness of the bitumen. Lower penetration indicated on the bitumen. The penetration depth is measured in tenths of millimeter. Specification for penetration graded bitumens. Normally stayed the penetration range for a grade. For example, 57 means a result of penetration that 25 degrees celsius. From 50 to 70 tenths of millimeter. Road designers directly used penetration to specify which penetration grade of bitumen should be selected. Depending on temperature conditions. Even if, choice of bitumen characteristics for road design is often more complex than that. The following indications are useful to understand which penetration grade will be the most suitable. If the temperature conditions are cold. Meaning an annual air temperature below seven degree Celsius. A 80/100 bitumen is typically to be used. If the climate is warmer, with mean temperatures between seven to 24 degree Celsius. A designer will tend to use, for example, a 60/70 penetration grade. And eventually, when the annual air temperature is above 24 degrees Celsius. It is necessary to use harder bitumen, for example, a 40/50 penetration grade. Let's now look at another type of characterization test. The softening point, also widely known as the ring and ball test. The principle of this test is to measure the temperature. At which, a sample of bitumen reaches a certain degree of softening under standard conditions. It measures the consistency of the bitumen's binder at high service temperature. Let's say 60/70 degrees Celsius. The ring and ball test is a standard test. In Europe, the standard reference is EN1427. Two horizontal disk of bitumen's binder test ensure the brass rings are heated. At a control rate in a liquid bath, while each supports are still warm. The softening point is reported as the mean of the temperatures. At which, the two disk soften enough to allow each ball enlocked in bitumen's binder. To pour a distance of around 25 millimeters. The determination of the softening point, helps to know the maximum temperature. Up to which a bitumen's binder should be heated for various road use applications. It is the maximal temperature for the use in road. So, a higher softening point ensures that bitumen will not flow during service. Higher the softening point, lesser the temperature susceptibility. Bitumen with higher softening point, is then of course preferred in warmer places. Also in general, the higher is the softening point, the lower is the penetration rate. Nevertheless, it is possible to increase the softening point separately from the penetration. By using for example, polymer modified bitumens or additives. In conclusion, penetration test and the softening point. Are the two main characteristics to measure the consistency of the bitumen. Each of them looks at different temperatures, corresponding to different application requirements. Penetration looks at ambient temperature, meaning, the average conditions on the road. Softening point, looks at the maximum temperature, from which bitumen is too soft to ensure its function of binder. The viscosity is also another very important test, to measure the consistency of the bitumen. It will be addressed a little bit further. So remind you, the softer the bitumen, the higher the penetration and the lower the softening point. In the European specifications, the bitumen is graded according to the result of penetration test method. A bitumen 50/70 is characterized by a penetration between 50 and 70 tenths of millimeters. Thank you for your attention. I will come back in the next video, dedicated to bitumen and its application. [MUSIC]