Road workers plan to use old asphalt for road repair more often
Rosavtodor is expanding the practice of using old asphalt when repairing highways. Technology of cold recycling, which allows to save the budget and reduce repair time, is used for more than 20 years in several regions. Now the authorities intend to expand the scale of its use. To check the effectiveness of the method, “generalization of the accumulated experience” and “selection of optimal solutions”, Rosavtodor ordered a scientific study for 26.4 million rubles. In the regions the technology is praised, but they note that it is more suitable for small roads outside built-up areas. In cities it is hardly applicable because of the large amount of dust and noise produced during recycling.

Rosavtodor held a tender to study the “practice of application” of cold recycling technology in the construction, reconstruction and overhaul of roads. The contract for 26,4 million rubles will be concluded with the association “Rosasphalt”, the president of which is the deputy head of the public council of the Rosavtodor Nikolai Bystrov.

Recycling in road construction means the technology of reuse of old asphalt. There are two types of recycling: hot recycling (with heating up the old pavement prior to paving) and cold. The latter is more common and cheaper. Old asphalt is milled and mixed with crushed stone, sand, various additives, cement or bitumen. Cold recycling allows to save building materials and not to spend money on their delivery, say in Rosavtodor. Besides, there is no need to remove and dispose of old material. This technology is widely known abroad. In Russia, it has been used since the early 2000s.

There are a large number of variants of the technology that involve the use of various techniques and source materials,” they say, “We need to generalize our experience and conduct additional field tests to prepare recommendations for selection of optimal solutions. The work with recycling should be done by “highly qualified specialists and organizations having the relevant experience and competence” in order to rule out premature road destruction, say the Rosavtodor. The agency reminds that a lot of regional roads have recently been transferred to the federal ownership (“Kommersant” told about this process), they require repair. “Cold recycling is a technology that allows to achieve the required level in the shortest possible time and significantly reduce the cost of the work, – explained in Rosavtodor. There is a need to increase the use of this technology. Its practical use will depend on the necessary funding”.

The technology can be used to restore the old gravel roads, said Alexander Vasilyev, the coordinator of the “Map of the dead roads” project. “Its use is urgent now against the background of budget cuts,” he said, “But the technology has not been fully investigated, often there are difficulties with the preparation of project documentation and calculation of mixtures. More research is needed. According to Mr. Vasiliev, garbage can be used for the bottom layers of the pavement: “The Dutch have been using everything they cannot throw away in the landfill.

As part of the contract, the market for cold recycling machines will be analyzed.

“The machines operating in Russia are mainly foreign made by leading companies from the US and Europe,” said Nikolai Krupin, the coordinator of the technical committee of the “Rosasphalt” association, “In the middle of last year there were problems with the supply of spare parts, but they are completely solved at the moment. We still have a limited ability to supply new machines from Western manufacturers, and we also have an opportunity to supply used machines in good condition. The share of machines from China has increased in the last few years, and their quality has grown. Russian manufacturers claim that they will be ready to launch a product in this segment in two years’ time, says Mr. Krupin.

The North-West Concession Company (operator of the 15-58 km section of M-11 highway) told Kommersant that mostly new materials are used for the repair works. “Our road surface must be particularly durable and wear-resistant due to increased loads and speeds, the requirements to asphalt concrete mixture are more stringent than on other roads, – say the company – All recycled asphalt we give to the contractor, and he disposes of the material at his discretion”. Moscow state budgetary institution “Highways” told Kommersant that recycling is not applied: this technology is more suitable for repair of out-of-town highways and local roads. The Ministry of Transport of the Moscow region told Kommersant that in 2019-2020 they repaired roads with weak foundations using recycling, now the technology is not used (the reason was not named in the department).

Road after the use of cold recycling gets a very hard and dense surface, said “Kommersant” head of quality control and innovation of the Directorate of Transport Construction (St. Petersburg) Andrey Demin, which complicates the subsequent repair of communications, which pass under the roadway.
The main place where recycling is used – suburban roads, says the expert.

“The reasons are simple: the works are noisy and dusty, four or five units of road equipment are working simultaneously, which is often impossible in conditions of urban development,” he explains.

Application of recycling “radically” reduces transport costs during repairs, reducing the damage from trucks carrying construction materials, say the Ministry of Transport of the Nizhny Novgorod region. Among the disadvantages of the technology the regional road builders note the “inconstancy of the material characteristics of the layers”, the considerable influence of the weather on the recycling process and the necessity of constant monitoring of the equipment operation with “consideration of unforeseen local conditions”.

Source: Kommersant https://www.kommersant.ru/doc/5796512
Ivan Buranov; Vyacheslav Kalashnikov, St. Petersburg; Roman Kryazhev, Nizhny Novgorod