Page 7 - Contractors World - International Vol 3 No 7

Panorama
Czech Republic
Speedy Work on Country
Roads
The rural roads near Brandýs nad Labem,
in the heart of the Czech Republic, about
25
km (15.5 miles) to the southwest of
Prague are crucial arteries to the rural
and agricultural areas of the country.
An assessment by regional authorities
indicated that these roads are in need
of repair.
That led to cold planing and paving work on a series of rural
roads near Brandýs nad Labem. Regional authorities required that the roads had to stay open during the work
because many are the only viable option, and the work had to be completed quickly (five days for one particular stretch
of road) to permit usual traffic patterns to resume as soon as possible.
USK s.r.o. was hired to handle the regional road project. The key for the firm was transferring both the knowledge and
the equipment often used in urban settings to the rural project said Ing. Jan Horák, the company’s chief executive officer.
The contractor recently completed a five-day section which is 4,200 m (2.6 miles) long and 6 m (20’) wide. Since half
the road was required to remain usable, USK needed a paver capable of working at a width of 3 m (10’). This paver also
had to be capable of laying down 800 metric tons (882 U.S. tons) of asphalt per day for five days. That meant the crew
and paver had to achieve good production levels.
Working at the 3 m (10’) width, a Cat AP555E Asphalt Paver was used to handle the paving. The open road also meant
the crew, particularly operators, had to watch out for traffic. The paver’s platform helped with this as the seats could
easily be turned for better visibility. Dual control stations enabled operators to switch seats without taking their eyes off
the important work at hand.
The ability to easily work from either side of the operating platform helped keep the paving train working at a quick
pace. The grip provided by the Mobil-Trac system also contributed to productivity.
Crews worked at a pace of up to 8 m (26’) per minute. They consistently reached the high end of the production
target. This is a very quick pace considering the mat thickness of 50 mm (2”). It requires all elements—trucking, paving
and compaction—to be in sync.
The paver worked for a half day in a single direction, then returned to that day’s starting point and laid down the
second half of the road with a longitudinal joint.
Planning played a key role. USK in particular focused on material supplies, counting trucks and loads to ensure
consistent delivery of asphalt. The steady delivery kept machines moving consistently, a crucial step in segregation
prevention.
The contractor determined the total volume of material. A project length of 4,200 m (2.6 miles) was factored in,
multiplied by the 6 m (20’) width of the road, plus exits and entrances, at about 4,000 metric tons (4,400 U.S. tons). The
deadline of five days meant the firm would have to place
about 800 metric tons (882 U.S. tons) per day.
Each haul truck had a capacity of 30 metric tons (33
U.S. tons), and had to travel 40 km (25 miles) from the
plant to the jobsite. A round trip took approximately 90
minutes to two hours, equating to four round trips per
truck per day. Six trucks were required to keep the paver
moving steadily.
The mix had a stone size of 4-8 mm (0.15-0.30”);
it arrived at a temperature of 160°C (320°F) and was
placed at 145°C (295°F). The material was end-dumped
into the paver.
Page 7
Contractors World - International Vol 3 No 7