ISTU scientists offer to road services of Priangarie to use mineral supplement to extend the life of asphalt concrete
Mineral powder based on polymer is developped by the scientists of the laboratory of innovative building and road materials at NI ISTU. The resulting supplement can significantly improve the performance of asphalt concrete, including durability, frost resistance and resistance to temperature extremes. As participants of the project notice, 4th year students of the Institute of Architecture and Construction at ISTU, Julia Saltanova and Kristina Lebedeva, the product may be a good alternative to expensive polymer asphalt.
Currently, scientists are working with Shelehov asphalt plant. The first batch of asphalt with mineral supplements will be released in late June.
"A significant rise of polymer asphalt compared with conventional bitumen is not only because of the high cost of the polymer, but also due to the difficulty of the process of uniform distribution of the polymer molecules in the bitumen. The problem is in the high viscosity of the bitumen and the slow rate of dissolution of the polymer”, said Yu Saltanova. “We offer a special way of distribution of the polymer in the asphalt concrete due to which it is finely granulated and covers the surface of the mineral powder. In the production of hot asphalt with the usage of modified powder polymer is dissolved in bitumen. "
K. Lebedeva stresses that it is difficult to finely granulate the polymer and secure it on the surface of the mineral material because of the strong plasticity. Furthermore, bitumen soluble polymers have poor adhesion to masonry materials.
"In this regard, it was decided to use carbon nanoparticles, which are molecular entities with unique properties. They effectively interacts with both the polymer and the surface of mineral fillers”, explains K. Lebedeva. “The modified nanoparticles and polymer powders are produced by mechano-chemical processing of dolomite powder, polymer and carbon nanoparticles. The nanoparticles are used as a product of dry removal of the silicon unit. "
During the experiments, the scientists were convinced that the best effect can be achieved by soaking the polymer in the industrial oil. As the plasticizer, the ISTU developers have used waste of production instead of industrial oil, which halves the cost of the product. According to the developers, the estimated cost of mineral supplements on the market will be about 7000 rubles per ton.
Students of ISTU noticed that studies have demonstrated the superiority of the product in comparison to conventional asphalt: temperature of softening of asphalt binding composition based on mineral additive is 70 °, frost resistance - 30 °, while figures of conventional bitumen are 50 ° and -20 ° respectively.
According to K. Lebedeva additional benefit of mineral additives prior to polymer alphalt is an unlimited shelf life.
"Polymer asphalt cannot be heated more than 10 hours, because it leads to degradation of the polymer and the demixing of binder. If asphalt binder is delivered to the plant in cold, it needs about a day to warm it up and we have to keep it heated several days in poor weather conditions (it is actually observed in the asphalt plants). Thus polymer asphalt is better to produce and use for several hours, and bitumen boilers must be equipped with a very efficient binder system of mixing. However, there no one asphalt plant with a specially equipped bitumen boiler in the Irkutsk region. Meanwhile, the modified powder, which does not have restrictions due to its shelf life, can be stored on standard equipment ", said K. Lebedeva.