The FAE MTH has been put to work as a multi-function head for tractors at the new Bolzano airport in Italy.
The runways which planes use to take off and land are the main infrastructure at each airport. Asphalt strips are designed and built according to precise criteria, starting with stabilising the underlying soil.
On many occasions and in different parts of the world, FAE soil stabiliser heads and multi-tasks have helped build these important structures. Recently, an FAE MTH did soil stabilisation work at the new Bolzano airport Italy, a strategic facility for northern region Alto Adige for tourism and commercial traffic.
The FAE MTH multi-function head for tractors ranges from 300 to 500 horsepower, enabling milling of rock slabs, crushing of stones, milling of asphalt and ground stabilisation, with a maximum operating depth of 50 centimetres.
Recently, domestic and international charter flights began landing on the runway again for business and tourism. Now, the need for additional work on the runway has reactivated the construction site in anticipation of the airport’s full reopening.
The company in charge of the soil stabilisation work for the runway at Bolzano airport is excavator contractor Brunner & Leiter, based in Valle Aurina, Italy.
The Project Manager for Brunner & Leiter (who has preferred to remain anonymous) at the Bolzano airport construction site explains the significant features of the work to Roads & Infrastructure Magazine.
“The FAE MTH worked with a Fendt 1038 tractor, stabilising 11,000 metres squared of soil to 25 centimetres deep. The machine could have gone deeper, but the specifications told us to work at this depth. The soil wasn’t very difficult to work, but there were still some medium-sized stones, which were no match for the MTH,” he says.
He explains the process of stabilising the soil in preparation for the build.
“First, we stabilised the soil using only cement. Before we started milling, we wet the ground slightly. Then, we went over it with the MTH at 0.3 kilometres per hour. This pace means we get the best quality mixing the soil. After going over the ground with the MTH, we went over it twice with two different rollers, first a 12-tonne one and then a nine-tonne rubber roller,” he says.
“We then wet the ground again and went over it one more time with a grader, which made the surface smooth and level at all elevations, ready to be paved. At the site, they were able to work 3000 metres squared a day, considering all the necessary processes, while the MTH alone worked for about five days.”
The Project Manager says he and his team were impressed with the performance of the machine.
“We are very happy with the MTH. Brunner & Leiter has four other ‘FAEs’, and they have always worked perfectly. They are completely reliable,” he says.
The MTH and MTH/HP is FAE’s multi-task head for 300 to 500 horsepower tractors. The gear transmission enables operation with constantly optimal levels of torque and power.
The Hardox counter blade and grill, mounted under the rear hood, provides the desired size of the processed material. The wide opening ensures high performance, even when working at depth.
One of the MTH’s most important technical features is the variable geometry chamber, a unique technology solution in the industry that allows soil penetration with the rotor alone.
The mobile rotor can be hydraulically adjusted from the tractor cabin. The chamber has a variable volume – the greater the working depth, the greater the volume of the chamber and the consistency of the grinding/mixture. Compared to a machine that plunges the frame into the ground, the variable geometry chamber reduces tractive force, which decreases fuel consumption and increases operating speed, saving time as a result.
The MTH can be fitted with a lighter G3 or R rotor. At the heart of FAE technology, these rotors grind up boulders, stones, asphalt, can homogenise soil and can consistently mix lime, cement or other binding agents spread over the stabilised area. The teeth are arranged in a unique criss-cross fashion to ensure evenly distributed force across the entire width, limited stress on the structure, reduced power absorption and uniformly dispersed material.
Interchangeable forged steel rotor hubs and guards made from easily replaceable components help to protect the rotor and tooth holder from wear. The rotors can be fitted with different types of teeth, depending on the application. Teeth are easily replaceable and interchangeable. Plus, an innovative technical solution allows the same asphalt shredding tooth (R/44) to be applied to both rotors.
The MTH options include two special high-performance water injection systems.
The Water Spray System cools and mixes as the machine shreds the asphalt. The cooling function limits the temperature of the rotor and teeth in contact with the asphalt, preventing it from overheating. Meanwhile, the mixing system makes stabilisation easier as the soil and stabilising agent are mixed with water.
In fact, at this stage, the addition of water to the mixing chamber improves binding between the stabilising agent and the soil, optimising the result of the consolidation work.
The Full Control System is a strong system with electronically adjusted nozzles, a self-priming hydraulic pump, proportional valves for adjusting water flow and a control display for settings, diagnostics and the machine’s operating status. This controls the depth, each nozzle and provides daily reporting on the project surface. The MTH also comes in a HP model for tractors up to 500 horsepower.
This article was originally published in the April edition of our magazine. To read the magazine, click here.