Road building economy drive

As with many other parts of the construction equipment world, there is a huge focus at the moment on new machines with the latest generation of low emission diesel engines. This year sees new laws take effect in Europe (Stage IV), Japan (Tier 4) and North America (Tier 4 Final) to reduce emissions from diesel engines used in off-highway machines.

The engine is such a central part of equipment that whole ranges are being re-launched at the moment, with other improvements being incorporated along with the engine change. However, price and fuel quality issues mean these machines are only suitable for the developed markets they were designed for, so manufacturers that want to sell around across the global have two separate ranges in their portfolio, one for rich countries and one for emerging economies.

In many cases, manufacturers are designing two completely different lines of construction equipment, but at the same time, there are some design improvements that are universal.

For example, Volvo’s Russian dealer Ferronordic Machines launched the full range of Volvo’s C-Series tracked and wheeled pavers – previously launched in Europe – for its domestic market in the first quarter of this year.

Volvo’ director of road machinery for Europe, Middle East and Africa (EMEA), Darren Fitch, said, “When it comes to paving quality, an even mat and a smooth finish, the C-Series is a true innovator. The electric screeds are fitted with a three or five circuit heating system, which allows for full temperature control of individual screed sections and fast heat-up times at low engine revs.

“This creative system empowers the operator when it comes to adjusting temperature across the screed – critical in terms of paving consistency.”

He continued, “Launching the C-Series of class-leading pavers in Russia is particularly exciting. Obviously the Russian Federation is an extremely important market in terms of road machinery and I believe this launch shows our commitment to road building customers across the Federation.”

The C-Series models being launched in Russia feature a new range of Stage IIIA-compliant Volvo engines designed to offer improved fuel efficiency even when run on diesel with a higher sulphur content, as currently found in that market.

Mr Fitch said, “The installation of Volvo engines means customers can now rely on a single partner to support their paving investment.

Meanwhile, as reported in the Equipment pages of the March issue of iC, Atlas Copco has launched a new range of rollers, pavers and feeders this year designed not only to be better than previous models, but also safe and environmentally friendly.

A good example is the company’s new Dynapac CG2300 roller, which has steering drums, rather than the central articulation of the Dynapac CC twin drum machines.

A key feature is the ECO Mode as standard, which is said to reduce fuel consumption by more than -15% and noise is also kept down through the use of a hydraulically-driven, temperature-guided cooling fan, which only operates when necessary.

For more details of this and other new road building machines from Atlas Copco, see the March issue of iC.

In the cold milling sector meanwhile, Wirtgen has a new version of its large W 200 planer, which has a drum that can be offset 400 mm to the left or right. The company says this feature of the W 200 Hi makes life easier on confined sites, as there is less need to manoeuvre the whole machine (which weighs 30 tonnes) and also allows contractors to work right up to the edge of obstructions like barriers and kerb stones.
The edge protector can be raised by 420 mm on both sides so that the machine can work flush with the edge even at large working depths.
In action

New technology in the sector is one thing, but as far as contractors are concerned, it has to have a benefit and a
pay-back.

An example of this has been seen in Saudi Arabia, where general contractor Al Mabani is laying much of the asphalt on the expansion of the country’s biggest airport, King Abdulaziz International Airport (KAIA) near Jeddah.

The first phase of the expansion is due for completion this year, with Saudi Binladin Group the main contractor. Al Mabani’s work started on the aprons and taxiways and then moved on to the runways, where it used two Cat AP1055E asphalt pavers with AS3301C screeds. The pavers placed five layers of asphalt, totalling 420 mm - two layers of polymer modified mix, followed by three layers designed using the Marshall method.

Pavers worked at a width of 6 m, and typically moved at 5 m per minute. They were the first pavers in the country to feature Cat’s Mobil-Trac System (MTS) undercarriage, which features fully-bogied support rollers that maintain contact with the surface regardless of irregularities. This means the asphalt mat that gets laid is smooth, with any dips and bumps in the ground not being translated into dips and bumps in the final surface.

An Al Mabani project manager stated there will be fewer final mat level issues due to debris on the paving surface. “We clear all debris to the extent possible, and the MTS is an extra assurance,” he said.
Meanwhile in Austria, a consortium comprising Granit and Swietelsky had to contend with all the usual hazards of live traffic as well as up to 1 km between access points while resurfacing a section of the A2 motorway near Schäffern.

The access problem meant it would be difficult to ensure an uninterrupted supply of hot asphalt to the paver, a Vögele Super 1900-2, using conventional techniques. To get round this, the contractors opted for a Vögele MT 3000-2 Offset Power Feeder with pivoting conveyor.

The feeder received the mix from trucks and continuously transferred it to the paver without physical contact, while the lorries navigated the site. With the capacity to accommodate an entire 25 tonne truck load of asphalt, the feeder always carried enough mix for an uninterrupted flow of material to the paver. This helped prevent the formation of problem areas in the mat, which tend to occur when a paver restarts work after a break.

This also meant the paver operator and screed operator were able to concentrate on the asphalt paving work, without worrying about the flow of material or having to deal directly with trucks.

Equipped with an AB 500 TV extending screed – the pave width varied form 4.75 m to 6 m - the paver placed two layers of asphaltic concrete, 70 mm and 75 mm thick, for the binder course to ensure a level base. These were followed by a 35 mm surface course of stone mastic asphalt.

“We achieved an outstanding degree of evenness thanks to the material feeder,” said Granit site manager Harald Zippe. “We were easily able to meet the client’s strict quality requirements.”
He added that the system helped reduce the team’s downtime on the project, with continuous working from 7.00 am to 4.00 pm possible.

“That made it easier to comply with the tight schedule and likewise made a key contribution to the outstanding results,” he added.

Telematics

The use of remote monitoring technology – telematics – is taking hold across the construction industry, and it was something Florida, US-based contractor The Turtle Companies found invaluable for its largest ever project. It won the contract to mill some 30 lane miles (48 km) of asphalt as part of the expansion of Interstate 75 (I-75) and although it had five milling machines working on the project, the company experienced less than 1% downtime.

Tim Hammer, maintenance supervisor with The Turtle Companies said, “Our Elite Maintenance Programme and a remarkable Guardian Telematics System on our newer milling machines has virtually eliminated unexpected downtime.”

The maintenance programme calls for three hours of maintenance after eight hours of milling, and in addition, all the work crew members have been trained to recognise and perform simple repairs as required.
The Guardian system meanwhile, is a telematics solution from Roadtec, which Turtle has fitted to two of its Roadtec RX-600e and two Roadtec RX-700e milling machines. It is designed to monitor the machine wirelessly in real time, providing information to the owner as well as Roadtec service staff.

“Diagnosing a machine equipped with the Guardian system is a much quicker and more efficient process,” Mr Hammer said. “The system’s Live Schematics lets me see all electrical circuits in a simple and efficient layout with real time status of all switches, valves and settings.

If I need to, I can make changes to the grade control system parameters from my laptop without touching the machine.”
David Ando, president of Turtle Southeast added, “Turtle has always been quick to embrace new technologies to help improve operations.

We had already been using a third party telematics system for almost 3 years. When we heard that Roadtec was developing their own system we were very excited. The Guardian Telematics System has become significant to our business. It allows us to be more efficient with what we have and decrease operating costs and increase profits. It also enables us to see problems before they become major which provides for scheduled maintenance and repairs before there’s a breakdown on the job and costs our customers money.”

Competitive advantage

These various case studies demonstrate that contractors can achieve a competitive advantage, perform work quicker and earn bonuses for higher quality work with the adoption of new road building technology. And with new machines coming onto the market thanks to new engine regulations, there is potential for more improvement in the future.