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Russian Projects Carried Out on the Initiative and with Technical Support of ITG
2006-2007 Perm: The Prospects of Using Hot MAC Mix in 2007 As Chinese experience shows, the use of MAC Technology in the form of cold mix only accounts for 10% of the total use of MAC Powder for road repair and construction purposes. The remaining 90% of MAC Technology applications are various purpose hot mixes. Being the most simple way to realize Multigrade technology advantages, cold mixes allow one to make the first step in exploring MAC applications that yields visible results within the first year. However, profit-wise, hot MAC mixes are the more promising technology. Russian companies that will be able to launch hot Multigrade mix applications in the national market are sure to gain a great competitive edge compared to other road construction specialists. In the US, for instance, the annual volume of hot MAC mix roadwork amounts to 1,000 miles. It is likely that the first experiment in using hot MAC mixes in Russia will be carried out in the Perm Region. The Regional Road Committee and Regional Government have shown great interest in attracting the most advanced road technologies available to date. MAC Bitumens are expected to be used to construct various layers of road pavements, including MAC-SMAs without any stabilizers (such as Viatop and Topcel). Through the following link, you may see the approximate MAC-SMA mix composition to be used in Perm: MAK_SMA_Perm. 2006 - Novosibirsk: Road Restoration with the Use of Cold MAC Mix (Made in a Paddle Mixer) The road reconstruction project involving the use of cold Multigrade mixes (MAC Technology) has been continued in Novosibirsk. The project aims at constructing and re-constructing a local roadway between Novosibirsk and Leninsk-Kuznetsky. In a similar project carried on in 2005, the mix was made using an asphalt concrete plant. This time, the mix was prepared in a paddle mixer at ambient temperature, without heating the aggregate. Compared to the asphalt concrete plant (even when it operates at a low 140F), the use of a paddle mixer yields a significant reduction in mix cost.
The application of 2 layers of cold mix made with different-sized aggregate allows not only to easily restore the performance characteristics of the restored pavement, but also greatly increase its load-carrying capacity.
The monitoring of the first experimental area re-constructed in August, 2005 has shown that the pavement has performed superbly both in very cold winter conditions (in temperatures as low as -51F), and in very hot summer conditions (up to +100F). After a year, the quantity of cracks measured by a standard method per 1 running km was 10 times less on the MAC Technology treated pavement than on the neighboring control area that was re-constructed using classical hot mix technology.
2005 Novosibirsk: Experimental Road Restoration with the Use of Cold MAC Mix (Made in an Asphalt Concrete Plant Mixer) In July-August, 2005, Facit Construction Company technically supported by Heritage Group and International Technology Group (USA), carried out an experimental project in constructing a pavement with the use of cold Multigrade asphalt concrete mix. Asphalt concrete Multrigrade mix is a mix made with gel-like binder which behaves as resilient bitumen in high temperatures and plastic (ductile) bitumen in low temperatures. Another peculiarity of this experimental project is the use of so-called open mix, whose materials dont contain dust particles or sand. This allows to create a strong stone framework that can take significant load from the traffic and provides increased rut-resilience.
The 800-meter area that underwent re-construction was located on the Novosibirsk Leninsk-Kuznetsky road on the border of the Novosibirsk and Kemerovo Regions. One of the peculiarities of the chosen area was the fact that the construction site was located 70 miles away from the closest asphalt concrete plant. Before the repair work, the area in question had been in critical condition and practically inaccessible to traffic. A test of the pavement foundation showed that the foundation was weak and unstable - and missing completely in some areas. This called for the application of cold 8-10 cm deep recycling with the use of bitumen emulsion. The remains of the old pavement were therefore used as part of foundation for the new pavement. The drainage system was restored simultaneously. Cold Multigrade mix was made in an asphalt concrete plant at aggregate temperature of 125F.
The construction of the experimental pavement was finished in August, 2005, after which the area was constantly monitored. Despite very low temperatures (up to -51F) that occurred during the winter, there was no significant cracking. The latest monitoring of the area dates back to May, 2006 and shows that the condition of the surface remains practically perfect.
The details of the experimental pavement application in Novosibirsk (2005) can be viewed through this link: Novo-MAC. |
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