Choosing road construction equipment and machinery, and in general any technique, most of us strive to read reviews, learn its capabilities, how it works. After all, new technology allows the use of new technologies. Although new technologies require new technology. So, for example, in the US, the question of changing the roadway is being decided.
In the US city of San Jose, which is in the very south of California and a few dozen kilometers from the border with Mexico, the recycler Wirtgen 3800 CR proves that its use for cold recycling is the most economical solution.
The principle of "time - money" directly concerns road construction. Especially in areas with high traffic congestion. And here the great advantage is the versatility of the machine and equipment.
An example of such a universality can be a recycler. The 3800 CR model from Wirtgen is capable of performing cold recycling with counter and tail milling in the "Upcut" and "Downcut" modes, respectively, and also operate as a high-performance road cutter. This versatility allows it to meet individual requirements in accordance with operating conditions and / or tender requirements.
In the "golden state" of California, the road wagon "Wirtgen 3800 CR with a capacity of 950 hp. restores the main transport arteries of the city of San Jose. The total length of the sections is 100 miles. The daily traffic load on them is from 12 000 to 35 000 cars. Therefore, the quality of the coating is very important, not to mention the fact that stopping this traffic flow can lead to a traffic collapse in the city.
Technology of cold recycling and associated milling
In order to obtain high quality laying, MCK Services Inc., performing road repair work, decided to use the method of passing milling, developed by Wirtgen Group: the milling drum of the recycler rotates in the direction of the machine movement, and not like in the case of counter milling, when the drum rotates against the movement. This ensures accurate control of the grain size of the processed material, especially in the case of very fragile, thin, old asphalt concrete roads.
In the framework of this method, the cold recycler Wirtgen 3800 CR moves in reverse, removing damaged layers of asphalt concrete 10 cm thick by 3.80 m wide with passing milling. The milling-mixing drum of the machine granulates layers of asphalt concrete and mixes it with a pre-distributed 1% cement.
Two tanks on the hoses are fed to the recycler water and hot bitumen, where with the help of compressed air from this was made foamed bitumen. The distribution ramp is controlled by microprocessors, which ensures that the added foamed bitumen is accurately fed into the mixing chamber for optimum processing of the granular material. Then, the ejectors placed on the rotor convey the prepared road mixture to the loading conveyor, which directs the material directly to the receiving hopper of the paver, which stacks it in accordance with the specified profile and position.
The maximum power built into the Wirtgen 3800 CR recycler concept ensures rapid restoration work. The loading system also has a high feed rate, and a rotary conveyor with adjustable height ensures accurate and efficient loading of the stacker hopper.
Profitability and environmental friendliness
After laying 100 miles of cold-recycling coverage on site, Bob Herrigan, MCK Services Managing Director, is pleased with the results: "With the Wirtgen 3800 CR, we were able to fully meet the technological and financial requirements of the San Jose administration."
The final figures speak for themselves: the use of cold recycling technology in place has made it possible to dispense with the closure of only part of the road and reduce the closing time of the carriageway, while the working hours of trucks were reduced by 90% (9,600 hours), which significantly reduced CO2 emissions and consumption fuel. Thus, the city managed to save about 1.5 million US dollars.
The conclusion of Frank Farshidi, the project manager from the city administration of San Jose, is also positive: "Cold recycling in place provides the highest quality, is economical, environmentally friendly and has minimal impact on the traffic flow."
https://t-magazine.ru/pages/coldrecycling
