FAA "ROSDORNII" took part in the organization of the next training seminar for road workers from all over the country.
The webinar was devoted to the topic of road maintenance, since new technologies and materials are being introduced throughout the country that allow asphalt concrete pavement to successfully "survive" the winter and off-season. Modern methods also reduce the number of accidents in the cold season, and also provide comfort for drivers and pedestrians. An online seminar within the framework of the Professional Development System (national project "Safe and high-quality highways) was held on November 10. The organizers were the FAU "ROSDORNII" and the Russian University of Transport. The webinar was attended by employees of the Russian Road Research Institute, as well as experts from the National Association of Winter Road Maintenance, various manufacturing companies, and representatives of the regions.
The online seminar started with an introductory speechAlexey Kovrov, Director of Organizational Activities of the CC FAU "ROSDORNII":
"We consider this topic to be as relevant as possible, since the implementation of the National Project "BKAD" showed that in addition to using modern technologies during repairs and reconstructions, it is very important to establish and effectively maintain highways so that the results of the work can be preserved as long as possible. In addition, winter is approaching, in some regions it has already begun."
Temperature changes, freezing and subsequent thawing of asphalt concrete pavement in the winter season, as a rule, leads to a sharp increase in the number of potholes on the roads at the end of the season. The first report of the webinar was devoted to the new generation of patching. Deputy Head of the Scientific and Technical Department of the FAU "ROSDORNII"Svetlana Polyakova spoke about the advantages of using "patches" to repair coatings. In the USA, they began to be studied and used back in the 90s to carry out effective operational repairs, and now they are also used in Russia. Such a material for patching has many advantages:
"Patches" should have high strength characteristics, increased corrosion resistance, that is, resistance to water, and have high coupling properties with the underlying layer. In addition, they must be workable. Thus, "patches" – these are long–term cold patch materials, convenient to use, which have advantages over traditional cold mixes," Svetlana Polyakova summed up.
In the FAA "ROSDORNIA" in 2019-2020, research work was carried out to assess the effectiveness of the use of the "patch" of foreign production, followed by the development of the organization's standard. The advantages of the material under study include the possibility of using a "patch" in adverse weather conditions: at low temperatures or with excess moisture on the coating (in the rain). The speaker illustrated this feature with photographs on the implementation of experimental work in Khabarovsk as part of the pit repair of potholes of considerable size filled with water.
Monitoring of the condition of the repair sites was carried out by the Far Eastern branch of the FAA "ROSDORNIA". The condition of the "patches" in the coating was assessed after 6 and 11 months. It was recorded that the "patches" were not lost during operation and are in good condition at the repair sites. This allows us to talk about the effectiveness of their applications.
Specialists of the FAA "ROSDORNIA" continue to actively study cold repair materials. The information collection "Domestic and foreign experience. Materials and technologies of pit repair of potholes of asphalt pavement", which contains an analysis of domestic and foreign practice of using repair materials and technologies over the past 5 years.
After the presentation, Svetlana Polyakova answered numerous questions from the audience about the cost of mixtures, the maximum temperatures for use and regulatory documentation. The next speech touched upon the maintenance of roads directly in winter. The data of numerous Russian and international studies presentedAnna Klimentova, Chief of Staff of the National Association of Winter Road Maintenance.
The audience of the webinar was presented with a graph of the dependence of the number of accidents on the coefficient of adhesion on the road surface. The minimum, we recall, is 0.3. This indicator is significantly reduced on icy asphalt, on rolling and rolling with sand. In such conditions, the risk of an accident is up to 4.5 times higher than on a clean, dry covering.
Such studies put an end to the dispute: leave the highway in a snowy roll or clean it to "black asphalt". In Sweden, an experiment was conducted by taking two sections of road identical in traffic intensity, number of accidents, weather and climatic conditions. One of them was kept for several years in a roll, the other used chemical reagents.
"It is natural that the number of accidents on the road cleared to "black asphalt" was lower, while the average speed of the flow of cars was higher. But scientists have also received a number of unexpected discoveries. The financial costs of cleaning were higher on the road that was under the cover of snow. This is due to the fact that if the road is intense, and you keep it under a dense snow cover, you are forced to process it with friction materials and grading much more often. In addition, the environmental damage from the road under the snow, oddly enough, was also higher, since the speed of cars decreased, and accordingly, the impact of exhaust gases on the environment increased," explained Anna Klimentova.
The speaker dispelled the myth of deicing reagents. Many consider them harmful to the environmental of course, but looking at the composition, you can see that this is just a misconception. After all, such a mixture is a compound of table salt, a common food additive calcium chloride, sodium formate, which is added to animal feed, and marble. Whereas a sand-salt mixture based on ordinary river sand, which is widely used in Russian cities in winter, is much more dangerous. Under the wheels of cars, it turns into a poisonous suspension with a high content of heavy metals (arsenic, nickel, cobalt). The content of harmful components in such a dust cloud exceeds the MPC by tens of times. They remain in a person's lungs for life, which threatens to reduce immunity and the risk of cardiovascular and oncological diseases.
Russia is now actively adapting to the international approach of winter road maintenance in order to increase road safety. He told about the experience of introducing new deicing reagentsAlexey Lykov, Director of the Moscow State University "DAEWOO No. 1" of Novosibirsk. The transition to new rails in the regional capital began in 2017 and took three years.
"Previously we used sand mixture, which has a number of disadvantages. This is low efficiency at low temperatures, after -10 it just stops working. River sand does not provide effective traction qualities on the road, and accordingly, safety suffers, the number of accidents is growing. Dust formation has already been mentioned. In addition, fine sand is easily transported by meltwater and in the form of precipitation penetrates into the storm sewer system, clogging it. And these are additional expenses for our already meager budgets," Alexey Lykov shared.
Realizing the disadvantages of the sand-salt mixture, the road services of the region first began to increase the size of the fraction of materials, then increased the volume of chlorine-containing components, which have a high melting capacity. And in 2017, the most suitable deicing reagent was selected. The result was not long in coming, the coefficient of adhesion was increased, and the dust content was reduced by 16 times. The information is confirmed by the conclusion of the environmental assessment. In addition, the cleaning time has been reduced, and the effect of it lasts much longer, which saves the budget. Novosibirsk is not standing still, the city has started using a two-phase reagent, which it works even faster.
Manufacturers of similar reagents also joined the webinar. Employees of UZPM Group of Companies told about the advantages of their products. Rudolf Ponomarev, Deputy Commercial Director, said that the Perm plant has its own research center, deliveries are carried out to more than 50 subjects of the Russian Federation, as well as to Kazakhstan and Belarus. About 700 thousand tons of material are produced per year. The products are approved by the state environmental expertise. The quality of the mixture is also confirmed by the FAA "ROSDORNIA".
Another product of the Ural Plant of anti-icing materials was also presented at the seminar, it allows you to deal with dangerous dustiness of the air in cities. There was a report about him by the General Sales Manager of UZPM GroupAndrey Chernyshkov. Dedusting compounds, which are produced in Perm, effectively remain on the road surface for 5-10 days in summer and autumn, and the effect of humidification lasts 5 times longer than from water. They are harmless to the environment. The specialist showed photos of the road in Kazan, where mixtures with a dust-suppressing function were used. In the images before processing, we see a dust cloud that disappears after using the composition. The effect is noticeable both after a few hours and after a few days.
As already mentioned, in winter, when it is not possible to prepare a mixture on the ABZ, cold asphalt concrete is used to maintain roads. He told about the peculiarities of their use in the conditions of the Russian climate on the example of manufactured productsArif Mammadov, Commercial Director of Olmix-Asphalt.
Cold asphalt at first glance is several times more expensive than hot and cast, the speaker stated, but its use eventually comes out much cheaper: production, rental of special equipment and the release of heavy machinery on the line is not required, since the mixture is sold ready for use. Thus, the repair of one pit costs an average of 150 rubles. In addition, cold asphalt can be used in extreme weather conditions and at temperatures from -20 C to +35 C.
In addition to new materials, the webinar also presented new equipment that is effectively used in Russian cities. Speaker from St. Petersburg on the example of the northern capital he talked about what kind of communal equipment is suitable for working in cramped conditions. The final report of the webinar presentedPavel Yakovlev, General Director of Palwood LLC. He listed which parameters are taken into account when choosing utility vehicles. Firstly, small dimensions, since sidewalks in the city center are usually extremely narrow. Since tiles are often laid on them so as not to spoil it, the equipment should not weigh much. But at the same time, it needs to be stable, have traction combined with the accuracy of the operation, so as not to damage cars in a narrow yard. The equipment in question combines many functions due to the easy change of attachments. There are more than 170 species. Such a machine can remove snow and load it itself.
About 200 people joined the conference "Modern technologies of road maintenance", 178 of them were representatives of 79 regions of the country. The online seminar took place on the site of the educational portal created by the FAU "ROSDORNII" and the Russian University of Transport. It is also posted there schedule of upcoming webinars on the most pressing issues of the industry.