Paving the way: new roads and repair work continue across Europe

26 January 2011

Fuel efficiency and noise emissions are issues for Volvo.

Fuel efficiency and noise emissions are issues for Volvo.

New roads and repair work continues in some areas despite the global economic situation, and new techniques and machines are there to move the industry forwards. Sandy Guthrie finds out more.

The desire for new roads across Europe to cope with ever-increasing amounts of traffic, coupled with the ongoing need to repair worn existing roads, provides a platform for the manufacturers of road building equipment to work from.

The economic situation has, however, seen to it that there are more projects in some countries than others.

Richard Owen, director of market support for road machinery at Volvo Construction Equipment Region Europe, said, "Road building in general depends to a significant extent on government funding.

"During the global financial crisis, various government stimulus packages had a relatively positive effect on the road building sector. As some governments in Europe now move into deficit reduction mode, however, there is uncertainty over short-term spending on roads, which is adversely affecting the industry in many parts of the region."

Repair work cannot easily be ignored, though, as Mr Owen pointed out. He said that where road maintenance was postponed or deferred, it meant that a failing road would go through additional seasonal cycles and - particularly after winter periods of freeze and thaw ­- there could be significantly more damage and additional cost when the repair was eventually made.

Pete Kulp, product manager at VT LeeBoy, is particularly concerned with road repairs.

He said, "Regardless of a road's design and build quality, virtually all asphalt pavement will eventually crack, either from extreme cold, or dry, hot weather. And that crack, combined with heavy traffic, will eventually turn into a full-blown pothole."

He said there were numerous methods to repair potholes, from the most basic "fill-and-go" techniques to the most complex, where a large area of pavement is removed and replaced.

Kulp claimed that spray injection patching, introduced in the early 1980s, had emerged as the choice method in terms of efficiency, quality and cost-effectiveness.

"Spray patching," he said, "is done via a low-pressure system, which delivers the necessary air, aggregate and emulsion at a rate of just three to four PSI.

"First, the pothole is cleaned and prepped. All water, dirt and any debris are removed. Next, the hole is sealed with a coat of liquid asphalt to help ensure a strong bond between the aggregate mix and existing asphalt. The hole is then filled with the mix, typically consisting of hot asphalt or liquid-covered rock, which bonds to the existing pavement. Finally, the patch is sealed with a dry coat of aggregate to enhance durability and longevity."

The spray injection process provided a faster option, he said, because the entire method was mechanised.

He added that the entire repair job could take just one minute from start to finish - making it up to four times faster than traditional methods."

There are new developments in pavers too. After a three-year research and development programme, Dynapac has unveiled its new generation of tracked asphalt pavers.

The new range comprises six models in the 2,55 m transportation class, offering paving widths up to 14 m, and Claes Ahrengart, president of parent company Atlas Copco's road equipment division, said, "We're launching probably the most important products for us."

The six-model range comprises four advanced SD models with electronic controls, while the two F machines come with electric controls and gas-heated screeds.

Thomas Hörnfeldt, Dynapac's vice president for capital equipment, described the F models as "rugged" machines, and the company expects the main interest in these to come from developing markets.

A common feature across both the F and SD machines to support this is the redesigned hopper, which has rounded-off internal corners to ensure asphalt does not stick.

A new feature is Dynapac's patented Safe Impact System - a bumper/roller mounted on the front of the hopper via two hydraulic cylinders, which acts as a shock absorber when trucks are backing up to the paver to tip in asphalt.

The main divergence between the F and SD machines is in the on-board technology. A key part of this is the engine. Dynapac has used Cummins units throughout, but whereas the SD machines will be fitted with Stage IIIB/Interim Tier 4 units for the European and US markets, the F series will take Tier 3 or lower units for developing countries.

There is also a difference in size and capacities, with the largest of the four SD units, the SD 2550 offering a 14 m pave width, while the F series does not get this big, with the F2500 offering a 9 m width.

Talking about the development of the new range as a whole, Mr Hörnfeldt added, "We have been talking to a lot of contractors to ask what the most important thing is, and they all said it's the cost of paving, along with reliability and servicing."

Volvo's Richard Owen agreed about the cost aspect. He said, "The current financial pressures on the sector are clearly increasing the ever present demand for improved productivity and efficiency," he said.

He added that Volvo Construction Equipment and environmental care were traditionally interlinked and he believed that this link would prove increasingly important to contractors.

"While striving to protect our environment, we also take our social responsibility extremely seriously," he said. "Through innovations in our equipment offering we believe contractors will be able to meet the performance needs of the future with minimal impact on either the environment or those communities affected by road rehabilitation or construction projects."

Fuel efficiency and noise emissions are both issues that Volvo Construction Equipment has addressed with the introduction of Smart Power electronic engine management on its existing range of pavers and soil compactors.

The system selects smart power mode on the EPM II control unit on start up, which then lowers the engine speed to reduce both fuel consumption and noise levels. Full power mode can then be selected by the operator when required.

Mr Owen said, "Smart Power addresses the fact that, for most applications, the high output capacity of the engine is not really required. With Smart Power mode selected, field trials have typically demonstrated fuel savings in the range of -15 to -35% depending on the working width and application. The system has the additional benefit of reducing noise emissions by a significant 3 dBA, giving Volvo what we believe to be the quietest large paver range available."

Wirtgen is launching two newly-designed slipform pavers onto the global market - the SP 15 and SP 25 models.

The SP 15 is already available while the SP 25 will go into series production from January. The two machines will replace the SP 150 and SP 250 models.

Wirtgen said the broad scope of applications offered by the SP 15 comprised all offset applications with a paving width of up to 1,80 m and a paving thickness of up to 1,30 m.

The SP 15 is equipped with three track units - two at the front, one at the rear. The standard SP 25 is supplied with three track units - two at the rear, one at the front - but is optionally also available as a four-tracked model. The paving mould can be positioned on the left or right side of the machine within or outside the width of the machine frame. This feature is said to allow both the concrete paver and the mixer truck to travel with the moving traffic without the need for any dangerous turning manoeuvres from the mixer truck.

Gomaco is about to unveil its newest paver - the GP-2400, which is described as the economical choice for contractors looking for a half-width concrete paver capable of slipforming widths up to 7,3 m wide.

The GP-2400 is also designed to be tight-radius capable, user-friendly, manoeuvrable, easy to transport from job site to job site, and quick to set up on site.

The new paver is the result of a contractor approaching Gomaco with a specific request for a machine capable of slipforming a tight radius. The new paver is equipped with 3 m Gomaco series two tracks capable of turning tighter than traditional length tracks on a paver.

The paver features the Gomaco 3100 series open-front mould and a telescoping frame that provides extra versatility. The GP-2400 provides contractors with a range of paving widths from 3 to 5 m, with the standard telescoping frame and paving widths up to 7,3 m with frame inserts.

The GP-2400 half-width paver is powered by a 129.5 kW, 6.6 Turbocharged Caterpillar diesel engine.

From Caterpillar itself, its high performance AP655D tracked paver is involved in projects across Europe, from Portugal, France and Spain to Germany and Norway. The ability to equip the machine with a choice of conventional steel tracks, or the flexible rubber Mobil-trac System (MTS), is said to offer customers a paver with exceptional manoeuvrability, high traction capabilities, rapid travel speeds and good flotation.

The machine provides three steering modes - one for paving, one for travel and a manoeuvring mode that permits the tracks to counter rotate, allowing the paver to turn within its own footprint. This Caterpillar-designed system permits operators to reposition the machine rapidly when moving to a new start point. It also enables the machine to access restricted job sites, including narrow mountain roads.

Portuguese contractor Jose de Sousa Barra opted for steel tracks. The AP655D was put to work in the town of Vilamoura, repairing the Avenida Cupertino de Miranda, the main street in this busy town in the heart of the Algarve. The company had to complete 1,3 km of paving work in a single day.

An AP655D was used by French contractor Braja on a narrow roadway in the Rhône-Alpes region of France. Working on a 7,1 km section between Villepredix and Leoux, where the elevation of the road rises from 450 to 750 m, the machine was able to lay 250 tonnes of bituminous concrete mixture in just 45 minutes.

While Norwegian contractors have traditionally opted for wheeled machines because of the greater mobility of the rubber-tyred models, the rubber tracks of the MTS-equipped AP655D had contractor Velde Aggregates keen to try this new technology.Bobcat,

Velde's AP655D was put to work first on a site close to Stavanger, laying 1 km of roadway with widths of 4 to 8 m. It reported that the machine had a good transport speed, as high as a wheeled paver at 16 km/h.

Bobcat has launched new 46 cm and 61 cm wide planers, which it said provided increased productivity for maintenance and repair work on asphalt and concrete surfaces.

Both the torque and horsepower have been increased compared to the models being replaced.

The new models are free-floating oscillation planers, and can be used with three different types of cutting drum ­- all-purpose, fast-cut or smooth-cut drums. The drums from the previous models can also be used on the new planers.

The new planers are approved for all current high-flow loaders, including the new Bobcat S850 skid-steer and the T870 compact tracked loaders. One of the key product improvements is in the hydraulic side-shift which has been increased from 66 cm to 76 cm.


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Andy Brown Editor, Editorial, UK - Wadhurst Tel: +44 (0) 1892 786224 E-mail: [email protected]
Neil Gerrard Senior Editor, Editorial, UK - Wadhurst Tel: +44 (0) 7355 092 771 E-mail: [email protected]
Catrin Jones Deputy Editor, Editorial, UK – Wadhurst Tel: +44 (0) 791 2298 133 E-mail: [email protected]
Eleanor Shefford Brand Manager Tel: +44 (0) 1892 786 236 E-mail: [email protected]