The SUPER Pavers’ Fastest Lap in South-East Asia
VÖGELE pavers resurface the new Formula 1 circuit in Singapore.
Preparations for the Formula 1 Grand Prix in Singapore are running at full steam. When the 900 HP racing cars speed around the city circuit on 28 September, 2008, they will find perfect road conditions thanks to the efforts of an experienced paving team. On this job site, the pole position is held by two SUPER 1600-2 pavers from VÖGELE. Several sections of the circuit have been resurfaced with a special asphalt mix that complies with the stringent requirements of the Fédération Internationale de l‘Automobile (FIA).
The two main contracts for carrying out the asphalt paving work were awarded to construction firm OKP Holdings Limited in Singapore. The work included resurfacing the road in the Marina Bay area, widening Raffles Boulevard and paving new wearing course on numerous public roads and the circuit itself. This involved parts of Raffles Avenue, St. Andrews Road, Fullerton Road, Nicholl Highway, Temasek Avenue and Temasek Boulevard. On these stretches, 5 to 5.5cm of the surface was milled off before the VÖGELE pavers placed 5 to 10cm of the special Formula 1 mix.
Special mix for Formula 1 circuits provides better grip
The Formula 1 mix is designated as F1 SBS (Styrene Butadiene Styrene) PMB (Polymer Modified Binder) and was developed for the extreme conditions of high-speed motor racing. The material is 80 percent more expensive than conventional wearing course mix, but provides greater resistance to shear forces and deformation. The Formula 1 asphalt mix was developed by Hanson Buildings Materials and contains a special polymer-modified binder with a significantly higher viscosity. It can withstand high temperatures without softening and displays a low level of rolling resistance. Its rough surface texture also provides extra grip for the Formula 1 racing cars. “You can‘t compare this material with mixes for conventional road construction. Placing it with the pavers was a major challenge for our paving team on account of its high degree of viscosity,” says General Manager of OKP Holdings, Mr. Or Toh Wat.
Strict tolerance of 3mm
According to the strict rules of the FIA, the surface evenness may not deviate by more than 3mm over 4 metres in the transverse direction measured at any random point on the circuit. What‘s more, special regulations apply to road markings on city circuits. These have to be removed at the braking points to prevent the race cars from skidding. The same applies in bends and at blind points of corners so that the drivers are not confused. Paving work has to be completed 90 days before the start of the race in order to allow time for the circuit to be inspected and approved.
Paving team quickly got to grips with the SUPER 1600-2
OKP invested in two new, modern VÖGELE pavers to ensure that all requirements of the demanding task in Singapore could be fulfilled and the paving work could be carried out as smoothly as possible. The SUPER 1600-2 pavers of the latest “dash 2” generation are capable of handling maximum pave widths of 8m. The paving team became quickly familiar with the pavers and NIVELTRONIC Plus®, the System for Automated Grade and Slope Control. “This was an important point. After all, the work on the 5.1km circuit had to be perfect from the very first metre,” explains Mr. Or Toh Wat.
SUPER 1600-2: Facts and Figures
- Maximum pave width 8m
- Laydown rate up to 600 tonnes/h
- Maximum layer thickness 30cm
- Transport width 2.55m
- Pave speed up to 24m/min.
- Travel speed up to 4.5km/h
- PERKINS engine rated at 100kW
- ErgoPlus® operating concept
Grade and slope control with the VÖGELE Big MultiPlex Ski
In order to comply with the strict demands made on evenness for the Grand Prix circuit, the paving team mounted a VÖGELE Big MultiPlex Ski on each of the tracked pavers. This modern sensor system for grade and slope control is based on the well-proven technology of VÖGELE‘s sonic grade sensor. The Big MultiPlex Ski offers numerous advantages over a single sensor: the arrangement of three sensors in a row allows a base to be scanned simultaneously at multiple points that are relatively distant from one another. NIVELTRONIC® Plus, the System for Automated Grade and Slope Control, derives a virtual reference from these measurements. The 3 sonic sensors mounted on the Big Multiplex Ski can cover a maximum range of 13 metres. This offers the advantage that the system is capable of identifying and levelling out long irregularities in the base. The system controls very easily from the ErgoPlus® screed consoles.
Expert know-how for the paving team
OKP Holdings delegated a paving team to the job site in Singapore that has already completed successfully a diverse array of jobs over many years and has a lot of experience working together. Nevertheless, the Grand Prix paving job presented the team with a real challenge. In order to prepare for all eventualities, proven experts in the field were also called in. On the one hand it was Dr. Low Boon Hwee, a materials expert from Hanson Building Materials, the company which had developed the Formula 1 mix, and two applications technology experts from VÖGELE on the other. They have a wealth of experience in all aspects of paving and already provided their expert advice at numerous Grand Prix circuits, including Hockenheim, the Nürburgring and the circuit in Barcelona.
Paving team impressed with the SUPER pavers
Once the test paving had been successfully completed, the actual resurfacing of the race circuit went smoothly. The OKP paving team was full of praise for their new VÖGELE pavers. Just like the actual race itself, resurfacing of the circuit was done counter clockwise. This means that the Formula 1 racing cars will always drive in the same direction as the special asphalt mix was placed. This minimizes rolling resistance and makes the circuit perfectly prepared for the race.
Paving “hot to hot”
The total width of the circuit is 15m, so that the two SUPER 1600-2 pavers were set up to pave widths of 7.5m each. A condition specified for the circuit was a perfect bond between adjacent strips. In order to flawlessly meet this requirement, the SUPER pavers placed the two strips hot to hot.
Quiet VÖGELE pavers easy on residents‘ nerves
As most of the paving in the city with a population of 4.6 million people was carried out at night, it was important to work as quietly as possible. This applied in particular to the construction machinery, which had been selected also according to noise emission aspects. In this respect, the modern SUPER pavers were the perfect choice. Their powerful PERKINS engines already run quietly in standard operating mode. And when selecting ECO Mode, which is more than adequate for a great number of jobs, noise emissions are reduced even further.
Assessment according to the International Roughness Index (IRI)
Once paving was completed, the circuit underwent a pavement condition survey in two phases in order to assess its ride qualities according to the International Roughness Index (IRI). The first inspection took place right after completion of the circuit and the second 6 weeks prior to the race. The IRI was carried out by an independent and accredited laboratory using drill cores. Now the race can start. Not only the paving team involved in the roadworks are waiting impatiently for the moment on September 28, when the red lights of the signal system extinguish and the first Formula 1 race in history starts under floodlights.
The Formula 1 Mix for Singapore
In Singapore, the high standards specified for racetracks were met by the special asphalt mix Type F1 SBS (Styrene Butadiene Styrene) PMB (Polymer Modified Binder). The mix was developed especially for this application after extensive tests.
This F1 mix contains a polymer-modified binder designed for the extreme conditions of high-speed motor racing and test circuits. The binder features higher viscosity and stiffness, a higher softening point and a lower penetration point compared to mixes used for conventional roads.
As shown in the wheel tracking test, the F1 mix has a higher resistance to deformation than asphalt mixes used in ordinary pavement construction. The dynamic creep test revealed that the road’s permanent resistance to rutting is higher, too. And due to the rough surface texture, the pavement features a considerably better grip.
Reference: SOUTHEAST ASIA CONSTRUCTION, Issue March/April 2008
Asphalt Mixes for Racing Tracks
Over the years, asphaltic concrete has established itself as the optimal paving material for all racing tracks hosting Formula 1 events. In the focus of these applications primarily are asphalt characteristics referring to the road’s surface properties and ride quality, such as skid resistance and evenness.
Skidding resistance is achieved, among others, by selecting aggregate with a high resistance to polishing. Used as a measure in this context is the Polished Stone Value (PSV). Aggregate with a PSV > 58 contributes substantially to excellent anti-skid properties. Asphaltic concrete is the preferred material for racing tracks as it generally displays a well balanced ratio of mega, macro and micro-roughness due to its aggregate composition with a high content of sand and no omitted-size grain, thus possessing good permanent non-skid properties. The International Roughness Index (IRI) is a standard for measuring pavement roughness. As a general rule applies: the higher the index, the better the pavement’s grip.
As far as perfect evenness is concerned, also a key characteristic of Formula 1 circuits, these projects call for sophisticated machine technology. The machinery, in conjunction with the appropriate asphalt mix, must be able to meet the requirements made on these specific contracts.
Shear strength and resistance to deformation are further properties of the pavement, which for racetracks need to meet far higher standards compared to conventional road construction. On high-speed circuits, the strain on the pavement are not high static or dynamic loads caused by heavy weights, but rather the horizontal shear forces introduced into the pavement by the braking and accelerating action of the 900 HP racing cars. Furthermore, the asphalt must feature high stability in order to prevent deformation in the heat of the high-speed races.
As a binder, bitumen blended with Trinidad Lake Asphalt or bitumen enriched with plastic additives (polymers) proved to be an excellent choice for racetracks. The special polymer-modified binders are perfectly suited to absorbing the extreme tangential forces exerted by the racing cars when braking, accelerating or taking tight bends at high speeds. The binders also feature high elasticity and have strong adhesion properties. Due to their high content of polymers, they are perfectly suited to meeting the stringent requirements made on racetracks in terms of resistance to deformation, aggregate/binder adhesion and flexibility.
Job Site Details
Resurfacing the city circuit for the Formula 1 Singapore Grand Prix
Length of circuit: 5.067km
Pave width: up to 7.5m
Layer thickness: 5 to 10cm
Special asphalt mix: F1 SBS
(Styrene Butadiene Styrene)
PMB (Polymer Modified Bitumen)
2 SUPER 1600-2 with
AB 500-2 TV Extending Screeds
The Singapore F1 Circuit
Race: Singapore Grand Prix
First Start: September 28, 2008, 8:00 p.m. local time