New asphalt pavers deliver better surface quality

With the 688 Bauma exhibition due shortly in Germany, much of the technical development in asphalt paving at present is in the market for tamper bar screed machines developed initially for European paving applications.

However there are new US style high production pavers also coming to market too and it is worth noting also that several major European firms now offer pavers developed specifically for North American customers.

Some of the US asphalt paver manufacturers are also looking to enter the world market with tamper bar screeds and US screed specialist 2599 Carlson has also admitted to working on a tamper bar screed.

A key market development in this regard comes in the shape of an alliance agreement between 2394 Volvo Construction Equipment and VT LeeBoys. This will allow 717 Leeboy to supply certain models pavers and road wideners to Volvo dealers under the Blaw-Knox brand. LeeBoy will also take full responsibility for product support of these machines, including existing units in the field.

The machines will be marketed under the Blaw-Knox brand under a five-year brand licensing agreement with Volvo Construction Equipment and distributed through Volvo road machinery dealers.

Volvo says that the deal allows it to concentrate its road machinery technical and engineering expertise and production operations on high-volume Volvo paving, compaction and motor grader equipment. At the same time Volvo hopes to benefit from the strength of the Blaw-Knox brand, which is well-accepted in North America, Australia and New Zealand. According to Volvo this move will give its dealers access to a broader product offering and allow it to compete strongly in the market place.

Production of the upgraded and redesigned Blaw-Knox RW100 and RW195D road wideners and PF150 and PF161 pavers is now gearing up at VT LeeBoy's facility in North Carolina. Meanwhile the deal is of strategic benefit to VT LeeBoy also as it will allow the firm critical mass to expand on its road paving machine production considerably.

In the iron

In terms of new machines, there is a lot coming to market. One notable change has been at Amman, which is now rolling out its recently acquired paver range, having bought the rights to the designs developed by Italian firm 2525 Antec. These are now being sold alongside 6791 Ammann's well-proven and sophisticated compactor range. The smallest unit is the compact APW1500 mini-paver, a wheeled machine said to suit small road repair jobs and resurfacing work where cables have been laid. Compact in design the APW1500 can work in single lanes with minimum disruption to traffic as well as in restricted space areas. This versatile machine offers paving widths of 250-800mm with an option to extend up to 1.65m and features a gas heated screed with automatic burner ignition and temperature control. It weighs 790kg and is powered by a Hatz diesel rated at 6.3kW, while it can produce 35tonnes/hour.
The new APW2700 paver is said to be the only wheeled machine in the 5tonne category and offers paving widths of 1.4-2.73m, while extensions offer a maximum paving width of 3.33m. Gas or electric screed heating is offered while power comes from a 201 Deutz diesel rated at 33.2kW and the machine has a capacity of 150tonnes/hour. The APW 3503 and APT 3501 are wheeled and tracked pavers for medium-sized jobs, with features including good manoeuvrability and high tractions drive systems suiting operations in difficult terrain. Customers can choose vibrating or tamping screeds with gas or electrical heating, while other features include automatic lighting and temperature control. These units weigh 7.4tonnes and 7.5tonnes respectively and offer paving widths of 1.8-3.5m and 4.5m with extendions, while power comes from a Deutz diesel rated at 51.5kW and maximum throughput is 230tonnes/hour.

172 Bomag continues to improve its paver range, offering machines that are now designed and built in Germany alongside the compactor line-up and which are better performance matched for optimum paving efficiency. Upgrades are now being introduced for the BF600 models while the firm is now offering its BF300 series paver in a wheeled version. The BF300 also comes with upgrades to the screed operation, also features of the latest BF600 and BF691 models. Compact and manoeuvrable, the BF300 offers a transport width of 2.5m, including attached extensions and side plates and comes with new screed operator stations also fitted to the BF600 and BF691.

The BF300 has a highly adaptable operating station and is offered with three different driveline options. There is a cost-effective 2x6 rear-wheel drive, a 4x6 model with additional drive on one front axle for higher traction force and a 6x6 all-wheel drive for use on difficult terrain. The BF300 models have standard screed widths of 1.7-3.4m while bolt-on side plates can provide maximum paving width of 4m. The electric screed has moulded heating elements for better heat distribution and prevention of corrosion to the heating rods, as well as a fast warming-up time of 20-30 minutes. The gas heating system on the S340 screed offers faster still warming -up times of 10-15 minutes.

Meanwhile the BF600 models now come with quick-change screed extension systems as well as front windshields with side guards. The high compaction HS screed on the BF600 finisher can now be mechanically to a maximum built-in width of 8m. To keep conversion times and costs low, the extensions are equipped with a quick-change system.

The driver's station on the BF600 can be extended on both sides while seat position can also be adjusted.

4018 Caterpillar Paving says that high mobility and fast set up times have been key targets during the development of its AP555E paver. Highly productive, the AP555E offers a maximum working width of 8m allowing it to be used on both urban and motorway paving jobs. With hydraulic extension the standard screed widths range from 2.55-5m but mechanical extensions can be fitted allowing a maximum of 8m. Operator visibility is said to be good and the machine has dual operating stations with the Advisor Monitoring System (AMS) and tilting consoles.

Paving speeds of 0-25m/min can be achieved and the customers have a choice of the firm's AS4251C or AS4252C screeds. These screeds are available with variable frequency tamper and vibrators and have electric heating. With the AS4251Cscreed fitted the machine weighs 16.7tonnes and with the AS4252C screed the paver tips the scales at 17.5tonnes. Power comes from Cat diesel delivering 106kW and which is Tier 3/Stage IIIA compliant while the machine also has a high capacity cooling system and a belt-driven generator. An auxiliary socket allows the use of additional lighting for night working and other electrical systems if required. The 190litre fuel capacity allows the machine to work through a shift without needing refuelling. Caterpillar's sophisticated material handling system with independent auger and conveyor controls ensure good material flow from the hopper and into the screed. Four individual pumps are said to allow each conveyor and each auger to deliver the exact amount of mix to the screed. The left and right conveyors in addition to the left and right augers are controlled independently ensuring mix demand is met when increasing or decreasing paving widths.

The Cat system is equipped with automatic speed control and three propel/steering modes, for paving, travelling and manoeuvring. A monitoring system on the left operating station offers project planning calculators, start-up checklists, engine operating conditions, and also lists fault codes for machine functions.

 Cat claims the Mobil-trac undercarriage provides excellent flotation and limits disturbance on soft base materials, ensuring uniform mat thickness. The large oscillating bogies and hydraulic accumulators are designed to progressively overcome surface irregularities with minimal tow point movement limiting the effects of curbs, mix piles, and manholes.

Customers can specify the Mobil-trac undercarriage with a choice of two belt designs. The tread-bar design provides good traction when grade conditions are soft, while the smooth belt gives better contact surface for good performance when pushing trucks and less base disruption when turning. The machines also have large oscillating bogies and hydraulic accumulators progressively overcome surface irregularities with minimal tow point movement limiting the effects of curbs, mix piles, and manholes 206 Dynapac is offering a development of its innovative twin layer paving system, as well as a new line of more conventional pavers. Although the twin layer Compactasphalt system is a niche market concept at present, the firm hopes to develop sales with its new version and also as the success of highways paved with this method encourage other contractors to use this approach. Dynapac has developed a new modular system that is considerably smaller than the original machine and is based on standard components, addressing the cost issues that ensured the earlier system was specifically suited to large highway construction jobs. The base for the new system is Dynapac's DF145CS paver, which is fitted with an additional materials hopper and screed and allows the contractor to pave widths up to 7.5m.

Aimed at more conventional paving applications, Dynapac's new SD Series tracked pavers are said to be easy to operate and productive due to high visibility. There are two SD Series, medium class pavers, the SD115C and SD135C, with production rates of up to 750 tonnes/hour and paving widths of up to 6m with hydraulic extensions while using mechanical extensions, maximum paving widths of 8m and 10m respectively can be achieved As with other new generation paving machines operator visibility is good while the seat can be turned through 45º to give a view of the hopper, auger compartment, screed, lane indicator and materials truck. The seat can also be slid and pivoted easily while the waterproof control panel has been redesigned for ease of use.

Power comes from an economical Deutz diesel that meets Tier 3/Stage IIIA emissions legislation and is rated at 140kW in the SD135C and 120kW in the SD115C. An optional eco-mode can cut fuel consumption further while the 400litre fuel tank allow the uints to run for a whole shift without needing to refuel operation. The machines are both fitted with 6m3 capacity hoppers and can lay a mat up to 300mm thick. Gas-heated screeds are offered as standard, although electric-heated versions are available as options and the firm has also developed a high compaction electric screed for specialised applications. Internal stabilisation bars for the screed's material guiding plates are said to reduce set-up times, while the VB510TV screed has been redesigned making it more compact. Dynapac features, such as the auger with its compact inner drive unit to minimise material segregation and the patented screed with four guide tubes, have been retained.

1252 Roadtec's new compact CP-90 Paver has been designed as a reasonably priced machine that is also able to carry out duties handled by larger units. The CP-90 shares features with existing pavers in the Roadtec range and, like its siblings, is suited to US-style high production paving duties. This machine offers paving widths from 1.2-4.75m and is equipped as standard with an electrically-heated, hydraulic adjustable EZ Screed supplied by Roadtec's sister company Carlson. The CP-90 paver shares the same rugged construction as its stablemates and is equipped with easily replaceable wear items to maximise uptime and reduce downtime. Hardox steel plating is used in high wear areas of the screed and hopper body to extend working life. The CP-90 is driven by a Caterpillar diesel delivering 63kW and which meets the necessary Tier 3 emission regulations. The diesel also drives a 16kW generator mounted on-board that provides current for the screed and lights as well as having sufficient power for auxiliary functions through a 120V AC socket. The consoles tilt down if required and the screed also features with extendable walkways, while options include beacon lighting and a canopy for the operator.

Roadtec also continues to develop its successful Shuttle Buggy materials transfer machine with the addition of new features intended to increase performance and add to the unit's versatility and capabilities. The Shuttle Buggy has been a success worldwide for Roadtec in the US, Europe and Asia in particular and the firm is keen to maintain its strong position in the materials transfer machine market with these latest updates. Key upgrades include a bigger unloading hopper that now has a width of 3.6m, although the width of the machine for transport remains 3m as before. The machine also has a twin operating station option, with platforms that raise hydraulically to provide better control over the truck unloading and discharge of materials into the road paver. These can be lifted vertically from 0-600mm and can also be extended out from the side of the SB-2500D by 600mm. Further options for the SB-2500D are planned and will include a CCTV package for the operator to see into paver hopper and unloading area, a bin level indicator and an automatic traction system.

For 1194 Vögele the main development in the paving sector is that the firm is rounding out its series 2 paver range with the top-of-the-range Super 3000-2. The machine shares the same all-round visibility and ease of use with the rest of the firm's Super -2 range. This is a highway class machine designed for major road construction and resurfacing projects as well as airport surfacing contracts. Because of its size and capacity it is powered by a six cylinder Deutz diesel rated at 300kW and this meets Tier 3/Stage IIIA emissions legislations. The engine also features lower fuel consumption than many smaller engines, while a 600litre fuel tank ensures that the machine can operate long shifts without need for refuelling.

The onboard generator is directly coupled to the transfer box and delivers 65kW, with plenty of power for the screed as well as auxiliary functions. The firm says that this paver delivers a maximum throughput of 1,500tonne/hour and according to head of marketing Roland Schug, "It's the biggest and most modern paver worldwide. We see the potential for a machine for laying sub-base and it can also be used for roller compacted concrete." Its massive throughput offers the chance for the machine to carry out large scale projects efficiently with this single machine able to take the place of two or even three smaller units. The Super 300-2 is able to pave a 500mm thickness in a single pass, allowing it to lay an entire lower course at once to widths of 5-6m.

Schug said, "It can be equipped with two types of screed, the AB600-2 or the SP300-2 fixed screed." The firm's AB-600-2 screed is offered in three versions, the TV, the TP1 with a single pressure bar and the TP2 with two pressure bars. The AB600-2 offers maximum screed widths with hydraulic extension of up to 9.5m. The huge throughput capacity also allows the SP300-2 fixed screed to pave widths up to 16m, allowing it to lay multiple lanes in a single pass. And the firm also offers hydraulic extensions that can be bolted onto the end of the fixed screed that can vary width up to 750mm, to pave around obstructions such as drainage or to provide angle joints at intersections. The paver features a 17tonne capacity hopper, with a 1.62m wide by 400mm high conveyor tunnel, while it also has high-performance augers to transfer large quantities to the front of the screed. High material throughput is also useful for sub-base paving jobs where large quantities of non-bituminous materials are involved and heavy-duty construction allows it to be used with abrasive materials. For use in sub-base and base course construction, a Heavy-Duty Kit is available as an option, with reinforced guards for the conveyor tunnel and the chassis, as well as modified auger blades.

As with other machines in the firm's paver range the new Super 3000-2 features the sophisticated Ergoplus control system. Four different operating modes can be selected at the push of a button: Neutral, Job Site Mode, Positioning Mode and Pave Mode, while a Memory feature stores last settings when exiting Pave Mode. This allows settings to be retrieved automatically after the paver's move on the job site. The operator's seat can be swivelled beyond the width of the paver for extra visibility while a GRP hardtop provides weather protection. Separate drives and electronic controls for the crawler tracks ensure constant tracking and precise turning.

Used in airport projects there are numerous facilities that could benefit from such a large capacity machine although for road construction, Schug said that China, India and Spain (and possibly Russia) are the main target markets.

The firm is also introducing a new version of its materials transfer vehicle, the MT300-2 that will replace the existing MT1000. This unit is able to take the full load from a truck and also offers n offset capability allowing it to load at 30º to either side so as to supply a machine working alongside when there is not enough space to tip directly into the paver. Schug said, "It has more capacity and more power than the machine we build today."

Volvo continues to develop its paver range with the development of tamper bar type models for the European market through its ABG line-up, as well as units for US customers. The tie-up with LeeBoy will help boost the US style products in the range while Volvo is also offering its own larger pavers for US customers. In Europe the firm recently unveiled B-series variants of its ABG7820 and ABG8820 pavers. These have been improved with increased output and reduced fuel consumption and are powered by the latest generation of Volvo diesel engine. Both pavers have Volvo D7 diesels delivering 170kW in the ABG7820 and 182kW in the ABG8820B. Paving widths range from 2.5-13m and the machines also feature Volvo's improved electronic paver management (EPM) system, which comes with a new smart power mode and provides efficient control as well as allowing effective monitoring of paving processes and machine functions.