Construction World February 2017

CONSTRUCTION WORLD

FEBRUARY

2017

ROLLERS AND COMPACTION

The route leads past centuries-old

buildings in the historical city centre,

modern skyscrapers and the port on

the Caspian Sea. So that the 22 racers

can move their fast cars appropriately,

machines from Wirtgen, Vögele and

Hamm have produced a high-quality

asphalt layer in the narrow streets and

on the wide boulevards.

Already months before the race in

Baku, preparations were in full swing.

Specifically for the Grand Prix, all facilities

were constructed in the city itself, such as

paddock including pit buildings, premises

for the teams, a media centre, the medical

centre and the grandstand. But undoubtedly

the largest project was the asphalt paving

for the 6,003-km-long track.

The team of the Azerbaijani general

contractor AzVirt LLC installed binder and

surface courses over 113 000 m

. The

highest requirements of pavement quality

were applicable, as the FIA, the organiser

of the race, does not compromise on this

point. After all, the Formula 1 cars reach

speeds at full throttle of over 350 km/h, at

the end of the round, on a less than 2-km-

long straight. And in such cases one thing

is critical: Even if you roar along a street

circuit, the asphalt must be homogeneous,

level and have excellent grip.

From cobblestone pavement to

high-speed track

At the beginning of the year Baku still

featured normal, paved city streets, some

of them quite a few years old, as well as

historic cobblestone pavement. To make

the track race-ready, Wirtgen large milling

machines were used, equipped with fine

milling tools and 3D control, to create a

surface with a defined profile, to the highest

standard of precision.

Along the old city walls, however, this

was impossible. This is where centuries-

old cobblestone pavement is to be found,

which should be left undamaged by the

race as it forms part of UNESCO world

cultural heritage. For this purpose, the

internationally renowned asphalt consultant

Rainer Hart developed a special solution

including carbon-reinforced asphalt.

Hot-to-hot sevenfold

The installation of the binder and

surface courses was done in possibly

record-breaking time, as AzVirt had an

impressive armada of Vögele pavers and

Hamm rollers at the start. The absolute

highlight was the hot-to-hot installation

in the area immediately in front of the

beach promenade: There, seven of the

eight SUPER 1900-2 pavers and 15 Hamm

tandem rollers built a 52-m-wide area in a

single operation.

HD, H+ and HD CompactLine

To obtain optimum surface quality, AzVirt

relied exclusively on tandem rollers

from Hamm during compaction. The

articulated machines of the HD, HD+ and HD

CompactLine series ensure, through their

very construction, even weight distribution

– an important prerequisite for high

evenness without ridges and cracks.

Another important advantage of Hamm

rollers is their excellent visibility. The large

rollers of the HD+ series primarily stand out

for their panoramic cabin. The machines

of the HD CompactLine come with a

‘wasp-waist’ front section that provides

an optimum overview of the working area.

Last but not least, the Hamm rollers score

with their outstanding side clearance. In

Baku, it enabled high-quality compaction

along the many kerbs, fixtures and walls,

right to the edge. In the process, the drivers

also appreciated the large track offset of

the articulated rollers that made it easy to

achieve precise compaction of the edges.

Oscillation protects historic

buildings

Another decisive factor for the high-

quality compaction was the use of

rollers with oscillation. This technology

involves dynamic compaction that

directs only few vibrations into the

ground around the roller. That was

crucial here, because the track is lined

with many historic buildings and below

the carriageway there are underground

car parks and subways. Therefore, in most

areas, conventional compaction with

vibration was absolutely forbidden.

“Instead the installation plan required

Hamm rollers with oscillation,” explains

asphalt specialist Hart and adds:

“Everything has remained intact and, at

the same time, we have achieved excellent

compaction results.” In Baku there was one

more reason for oscillation compaction:

the special movement of the oscillating

drum produces very flat surfaces, with good

initial skid resistance. Also thanks to this

technology, AzVirt was able to meet the

extremely high levelness requirements of

3 mm on a 4-m-long straight edge.

The best city streets in

the world

The final quality check revealed that on the

originally inhomogeneous city streets, a

first-rate pavement has been laid. “Accord-

ingly, thanks to the Formula 1 race, Baku

currently has, without doubt, the best city

streets in the world,” commented Hart.



Refining a

DEMANDING F1 STREET CIRCUIT

On 19 June 2016, the Formula 1 once again broke new ground: for the

first time, a race was held in Baku, the capital of Azerbaijan. Instead of

building a new track somewhere in the open countryside, the German

circuit planner Hermann Tilke, who had already planned the track in

Shanghai in 2004, designed a demanding street circuit with 20 curves,

a double chicane and an uphill section.