WIRTGEN Cold Milling Machines Rehabilitate the International Airport in Kuala Lumpur

Kuala Lumpur International Airport (IATA airport code: KUL) is one of the 30 busiest airports in the world and is also the largest airport in Malaysia with a capacity of 75 million passengers per year. Located about 50 km from Kuala Lumpur, the country’s capital, KUL serves as the “gateway to Southeast Asia” for countless travelers.

The airport has three runways, each about 4,000 meters long, which are used by more than 60 airlines. The first two runways were completed in 1998, the third in 2014. Then, in 2018, Malaysia Airports announced it would begin rehabilitating the runways under the KUL Runway Sustainability Master Plan to ensure that KUL’s flight operations remain safe and offer a consistent level of service over the long term.

In 2020, the contractor completely rehabilitated runway 3 after extensive maintenance work was carried out as part of the plan. Afterwards, in the fourth quarter of the same year, the company received the go-ahead to begin work on the first complete rehabilitation of runway 1, including the adjacent taxiways.

The rehabilitation measure was scheduled for completion in 2021, with a total of 44,000 m³ of asphalt needing to be removed and repaved. For the complete rehabilitation of KUL’s runway, contractor Nippon Road opted for an effective fleet of machines from the Wirtgen Group.

WIRTGEN cold milling machines deliver outstanding performance at Kuala Lumpur International Airport

Airport projects of this magnitude generally require high-performance, heavy-duty machines. Nippon Road has been carrying out demanding work of this kind for many years. Ir Wan Zainuddin Wan Omar, general manager of Nippon Road and also KUL project manager, reports: “I always insist on maximum machine productivity, reliable service, and uncompromising quality – and that’s exactly what Wirtgen consistently delivers.”

Based on the company’s past positive experience, they therefore opted for innovative cold milling machines from Wirtgen, pavers from Vögele, and rollers from Hamm for this project as well. The large-scale removal of asphalt from the runway was carried out by a fleet of Wirtgen milling machines designed for high performance and consisting of both tried-and-tested and state-of-the-art technology: several large milling machines with a milling width of 2.0 m – two W 195s, one W 205, two W 1900s – as well as a W 1000 compact milling machine with a milling width of 1.0 m. With a total output of around 3,000 PS (2,200 kW), the machines then met the challenge – the area to be milled extended over a length of approximately 4,000 meters and a width of 60 meters; and the company needed to remove 44,000 m³ asphalt in total.

Due to the much higher load in the central area of the runway caused by the weight of the landing aircraft, Nippon Road’s milling experts defined two areas, each with a different milling depth. The first area encompassed the central corridor measuring 18 meters wide, and the contractor decided on a milling depth of 25 cm for this section, which was continuously milled in two passes – first at a depth of 10 cm, then at a depth of 15 cm. The two outer strips of the runway, each 21.0 meters wide, formed the second area – here, the company removed a 7.5 cm thick asphalt layer in a single pass.

The W 195 and W 205: Two Perfectly Equipped Cold Milling Machines

All of the machine models used feature high engine power and exceptional milling performance. This allowed the cold milling machines to be used with flexibility wherever they were needed. Equipped with a two-meter standard milling drum, the W 195 and W 205 large milling machines, for example, can each mill to an incredible depth of 33 cm.

The milling drum speed on these models can be set to 104, 116, or 129 rpm, depending on the requirements, via a selector switch directly from the operator’s platform. While the low speed of 104 rpm is the right choice for achieving maximum milling performance with reduced fuel consumption per cubic meter of milled material and low pick wear, the middle milling drum speed of 116 rpm is best for standard milling jobs such as removing surface layers. This speed also produces more favorable grain sizes in the milled material. The high speed of 129 rpm is used for milling thin pavements at an extremely rapid advance rate.

Furthermore, the milling fleet also had to contend with a PMA material that was extremely resistant – due to the bitumen-modified asphalt’s many years of continuous use. Considerable cutting forces are generated when milling these hard layers. This means selecting the right round-shank pick for the job is essential in order to achieve maximum milling performance and a long tool life. The pick is selected based on the material properties and rock hardness in an individual application consultation. In this case, Nippon Road and the sales and service company Wirtgen Malaysia agreed to the use of genuine Wirtgen round-shank picks with a high-performance carbide tip.

Always the Best Milled Surface with the LEVEL PRO PLUS High-Precision Leveling System – For Effortless Asphalt Paving

The main objective, in addition to the high-performance removal of the entire old surface, was to precisely maintain the milling depth. To achieve this, the W 195 and W 205 come standard-equipped with the intuitive LEVEL PRO PLUS leveling system – leveling is one of Wirtgen’s key technologies. The LEVEL PRO PLUS high-tech leveling system developed in house by Wirtgen is fully integrated into the machine’s control system and continuously compares the current milling depth with the preset target value.

If the system detects deviations, they are dynamically and proportionally corrected. The actual milling depth is determined via optical or mechanical sensors that continuously scan a reference surface. In this context, a wide variety of sensors can be used: cable, hydraulic cylinder, sonic, and slope sensors or laser and ultrasonic ski sensors as well as multiplex systems. The LEVEL PRO PLUS leveling system offers easy one-hand operation using the rotary knob, and the menu can be configured as desired.

Fully integrating the leveling system into the machine control system also enables a high degree of automation and offers many automatic functions that make the operator’s job easier, as well as additional features for faster work processes. “Operating LEVEL PRO PLUS is both simple and convenient. Thanks to this system, the milled surfaces were immaculate – the cold milling machines produced a uniformly milled, even surface at Kuala Lumpur International Airport. This was a top priority for us, as it enabled us to pave the new asphalt layer smoothly and without any expensive subsequent finishing work,” added Ir Wan Zainuddin.

Quickly Clearing the Milled Material from the Site – Environmentally Friendly Recycling with WIRTGEN Cold Milling Machines

Front loading of the milled material from all of the cold milling machines involved ensured optimum truck logistics throughout the entire milling operation – continuously filling the waiting trucks kept the milling process flowing smoothly as the trucks rotated on the fly. The milled asphalt material was then reused in an environmentally friendly manner at a nearby road construction project.

After all of the scheduled milling work, including surface cleaning, had been completed successfully, Ir Wan Zainuddin was happy to confirm: “Once again, Wirtgen cold milling machines have proven to be extremely reliable during job site operations. And in the unlikely event that a component should fail, Wirtgen Malaysia immediately sends spare parts, components, or qualified service personnel to the job site. In this case, the service technician assigned to the project was on site within an hour. The Wirtgen Group machines played a significant role in the success of the rehabilitation project, but without the perfect collaboration between the Wirtgen Group, Nippon Road, as well as KUL, we never would have completed the project so smoothly.”

Pavers from Vögele and rollers from Hamm subsequently took care of the high-precision paving and professional compaction of the new asphalt surface.