A series of online conferences is being held again on the basis of the scientific Institute
The first conference is dedicated to the introduction of the technology of volumetric and functional design. According to tradition, the leading experts of the FAA "ROSDORNIA" presented their reports at the webinar, but this time a representative of the Orenburg Region also joined the meeting, where they have already switched to new technologies. The head of the industry of the region spoke about the process of transition to "new rails", about the difficulties and results of restructuring the work of road workers in the subject.
The opening speech was made by Igor Astakhov, Deputy Chairman of AVTODOR Group of Companies. Due to the fact that the meeting was held online, the speaker was able to present his speech during a working trip, stopping on the Moscow-St. Petersburg highway. He noted the high quality of the roadbed on the Tavrida highway, which, by the way, was built according to the method of volumetric and functional design.
Igor Astakhov reminded the audience about the advantages of this method. The main thing is that thanks to modern equipment and an innovative approach, it allows you to choose the optimal recipe for the ratio of components asphalt concrete mix for a specific road: taking into account the climatic conditions of the area and the load on the roadbed. Progressive devices also help to determine the technological parameters of the mixture both during production and during installation. Another plus is that the new standard makes it possible to successfully use local inert materials in the region. For AVTODOR Group of Companies, the method of volumetric and functional design in the repair and construction of roads is now a priority, for this purpose certain changes have taken place in the company:
"Together with the expert community, we have prepared a program for additional training of personnel. Because we understand that if people are not prepared, they will not be able to work with technology. In addition, we are engaged in completing branches with the necessary equipment, working with ABZ and directly at the places of laying asphalt concrete mix" - Igor Astakhov shared.
The company plans for 2020 to set up five experimental sites of one kilometer each in order to study the properties of binders under conditions of prolonged aging during real operation. The transition to a new technology will significantly to increase the service life, with its use, the inter-repair period will be 12 years. These are the new requirements, and only by following modern technologies, they are feasible.
Then I joined the webinar Olga Vorobyeva, Deputy Director for Organizational Activities of the BCC. Her report was devoted to the reasons for the need to switch to mixtures designed by the volumetric-functional method, as well as practical aspects of design and testing.
The speaker clearly and in detail demonstrated the differences between outdated and modern methods. First, in the regulatory field, Olga Vorobyova compared the points of the old and new GOST. Then, in the presentation, it was possible to see the differences of ready–made samples, some were made according to outdated but familiar standards, while others were made by the volumetric-functional method on a gyrator. This device works at an angle, creating a pressure of 600 kPa, which completely simulates the compaction of the mixture by rollers. With the old methods, the pressure is much higher and occurs at a right angle. The result is in the photo, the sample created according to the old GOST is re–compacted.
"What is happening in fact, what does it threaten us with? The mixture that has just been laid according to GOST 9128 and compacted, it is, in fact, already destroyed! Because we have crushed the mixture, and this is due to the rapid destruction of our asphalt concrete pavement. Most often, this is the rutting and removal of material from the road surface, especially in winter. We are talking about the harm of tires, and tires, in fact, just disassemble the small particles crushed by our rollers and carry them on wheels," explained Olga Vorobyova.
The speaker again reminded that it is necessary to switch to new technologies in a comprehensive manner, giving an example of a favorite way of the regions to lay asphalt concrete mixture of type SMA for the top layer of the coating, hiding outdated asphalt type B under it, which leads to even faster destruction of the canvas. However, if the mixture is designed on a gyrator, it can be tested by simulating the load from the operation of asphalt concrete over a 20-year period.
The following continued to tell about practical tips at the stage of production of mixtures, as well as at the time of laying, rolling and quality control Speaker, Alexander Tikhonov, Deputy Head of the Department for the Development of Scientific and Technical Potential of the road industry of the FAA "ROSDORNII".
Speaking about the problems that a contractor may face, the speaker was among the first to name the selection of bitumen. He explained that since the warranty periods for constructed roads are increasing according to the new standards, but their transport load is only increasing, it is necessary to change the approach to the assessment of bitumen binder:
«Let me give you the idea that PG is not something qualitatively different from BND. Very often, during business trips to the regions, we are faced with the position that PG is something expensive, rare, it is nowhere to be found. This is generally some kind of new unique bitumen. In fact, this is not the case. PG, in English, Performance Grade is just a set of characteristics. One of the main ones is the upper and lower limits of the operating operating temperatures of bitumen. That is, any BND bitumen has PG characteristics, we just need to determine them," Alexander Tikhonov dispelled the myth.
To do this, he offered contractors a qualitatively new way of interacting with suppliers of bitumen binder. Namely: when concluding a contract, order additional tests with the results indicated in the passport. And then it will be possible to accept the material taking into account its PG characteristics. Road workers will be able to check their compliance with the ABZ in an hour and a half using only one device – the Brookfield rotary viscometer, which is used to determine dynamic viscosity, since this parameter is a kind of "fingerprint" of bitumen.
You can also conduct a study of the characteristics of the bitumen binder by contacting the head office of the FAA "ROSDORNIA". About this in his report he said Sergey Stuk, Head of the Laboratory Support Department of the CC FAU "ROSDORNII". His speech was devoted to advice on equipping testing laboratories for the selection of compositions and quality control of asphalt concrete.
"I would like to note that the FAA ROSDORNII, as an Industry-wide Competence Center, is ready to conduct tests for determining the PG characteristics of bitumen binder in samples free of charge, sent by the subjects. We will conduct a study and issue a conclusion. Such work is being carried out, more than a dozen samples of the binder have already been tested, given that the work has just begun," Sergey Stuk suggested.
A laboratory complex capable of conducting the widest range of tests of road-building materials has been created on the basis of the FAA "ROSDORNIA". It has equipment for determining the grain composition of the mixture, as well as for testing asphalt concrete samples, for example, for water resistance or resistance to track formation.
In addition to the central laboratory located in Moscow, the branches of the scientific institute are also provided with stationary and mobile complexes.
One of the most anticipated reports of the webinar was the presentation of Dmitry Khusid, director of the State Institution "General Directorate of Road Management of the Orenburg Region", he spoke about the practical experience of translating the work of the road industry in the region to modern technologies. At the moment, all objects of the National Project "Safe and high-quality highways" in the subject are repaired and overhauled using volumetric and functional design. This is more than 143 kilometers of roadway.
First of all, the speaker told about why the Orenburg region decided to try a new method:
"The first thing that attracted us in this technique is the forecast of the behavior of road surfaces in a long time period, a forecast that takes into account the actual operation of the coating with reference to the type of congestion of a particular road, taking into account climatic, weather features of the terrain. This is very important for us, the Orenburg region is located in a sharply continental climate. We live, as they say, from 40 to 40. +40 in summer, -40 in winter," Dmitry Khusid said.
Due to such climatic features, roads in the region were quickly subjected to plastic, fatigue and low-temperature deformations. These problems are faced by most subjects across the country. And if the Orenburg region did not experience a shortage of high-quality inert materials, then choose the right bitumen it didn't work out for many years. The ability to select them by PG has become the second and decisive factor for the transition of the region to volumetric and functional design. This condition allowed the bitumen binder to be selected not according to abstract characteristics, but according to the most important – the temperature corridor.
After making a strong-willed decision, the Orenburg Region industry began a gradual transition to new technologies. We started with the purchase of the necessary equipment. So the first two laboratories appeared in the region: stationary and mobile. The latter is equipped with a gyrator and special devices for express analysis right on the object. We held auctions and started work with an experimental section of 6 kilometers in length of the Nizhny Pavlovka-art. regional road. Kargala. The SMA-16 coating type was used. After a year of operation, the coating remained unchanged. We started to modernize the industry, it took a year and a half.
"Now our largest contractors are equipped with their own laboratories, there are 8 of them in the region, they meet all the requirements. I want to dispel the myth, many believe that in order to reconfigure the work of the ABZ, large financial injections are needed, what needs to be purchased expensive equipment. In fact, it does not require large expenses," Dmitry Khusid stressed.
Photo from Dmitry Khusid's presentation: laying of SMA-16 mixture at Orenburg-Belyaevka airport
Currently, the Federal State Educational Institution ROSDORNIA is considering options for creating a mentoring system for regions so that subjects who effectively implement new technologies can share their experience with neighbors who are close in resource and climatic conditions.
Let's add that 80 regions joined the webinar dedicated to the volumetric-functional method of designing the roadway. During the online conference, they could also ask the experts their questions. This was only the first meeting with the regions in a series of webinars of the FAA "ROSDORNIA". The following conferences are devoted to the specifics of volumetric design standards, regulatory regulation of life cycle contracts, the creation of intelligent transport systems, current problems of design and construction of bridge structures and much more. The recordings of the reports become available after the end of the conferences in the Institute's community on the VKontakte social network.
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