Developments in asphalt paver performance
First publishedin World Highways
The new BOMAG BF800 shares features with the existing BF300 and BF600
Key additions will boost the asphalt paver offering for customers, Mike Woof reports
There are a number of key players in the asphalt paving market that see the value of investing in design, technology and performance. For customers this has resulted in a wide variety of high quality, high performance machines to choose from. Ammann
is one of the newest entrants to the paving equipment market, with a range that compliments its compaction machine range. The firm has revamped its entire paver line-up since it bought up the Italian-designed Antec range. The upgraded AFW/T 150, 270, 350 and 500 models now have improved drive and control features, making them easier to use and more progressive in operation. Stability has also been improved, boosting paving quality while the machines are now integrated into the firm's spare parts system, using many parts from Ammann's compaction machine range.
The ultra-compact AFW150 mini-paver is the smallest machine in the range, weighs 790kg and can pave widths of 250mm - 1.8m, suiting it to trench repair work or car park applications. The larger AFW/T 270, 350 and 500 models are offered in both wheeled and tracked variants and the wheeled models have four wheel drive and six wheel drive options.
All of the pavers in the Ammann range can be fitted with a vibratory screed or a tamper/vibratory screed, with both electric and gas heating options. that can be heated with either gas or electricity. The AFW270 (wheeled) and AFT270 (tracked) models compete in the 5tonne paver class, with extending screed widths of 1.4-3.33m. The AFW350 and AFT350 are in the 7.5tonne class and have paving widths from 1.83-4.5m. The AFW500 and AFT500 are in the 15tonne class, with paving widths from 2.55-6.5m. BOMAG
is extending its paver range with the addition of the new BF800 model, which shares features with the existing BF300 and BF600 models. This new machine weighs in at 20tonnes and is being offered both in wheeled and tracked variants, with the former featuring a 6x6 drive as standard. High output is claimed for this machine, which can offer a 10m maximum screed width for the tracked variant. The machine is offered with the firm's S500 and S600 electric screeds as standard, which offer paving widths of 2.5-5m and 3-6m using hydraulic extension. Mechanical extensions can also be used to allow paving widths of up to 10m and these can be fitted without the need for complex braces as they feature quick fit slide couplings, saving installation time. The cast electric heating elements are said to be robust and durable and provide an even distribution of heat throughout the plates, cutting heat-up times.
High performance screeds are said to ensure good paving performance on the new Dynapac machines
The BF800 models come with a high-capacity hopper and wide bin width for efficient loading, while material flow from bin to screed is said to be smooth and precisely controlled by a hydraulic front flap, a proportional scraper belt, proportional augers and a hydraulic auger height control. Control is provided on both sides from new side-mounted, adjustable operator stations and allow sensors for the scraper belt and augers to be selected and controlled. The new diagnostics system detects and highlights problems with material flow and allows the operator to take action where required.
These pavers come with the firm's ECOMODE machine management system, with four operating modes that help optimise performance and reduce fuel consumption. Other features include ease of maintenance, with good access to hydraulics, electrical and electronic systems and the engine. To help extend component life an automatic central lubrication system automatically supplies lubricant to high load areas such as screed, auger and auger height adjuster.
Meanwhile Dynapac is extending its paver range, with six new tracked models as well as a wheeled variant. The six tracked pavers can tackle paving widths from 2-14m and the firm is offering a choice of sophisticated models as well as basic versions. These are built on a modular design and share the same basic chassis, with working weights from 18.5-19.6tonnes. The sophisticated SD2500C, SD2500CS, SD2550C and SD2550CS tracked models and SD2500WS wheeled variant all feature advanced PLC-based controls. Meanwwhile the conventional models are the more basic F2500C and F2500CS pavers.
These new machines benefit from improvements to ergonomics and visibility as well as the low emission Cummins diesels. The pavers feature power ratings from 110kW or 129kW in the basic F2500C and F2500CS models to 176kW or 194kW in the more sophisticated SD2550C or SD2550CS models. Visibility is improved to the hopper and screed and the operator station can be slid from one side of the deck to the other. The largest machines offer throughputs of up to 1,100tonnes/hour and maximum paving widths of 14m when using mechanical extensions. Customers can choose gas or electric heating, with the latter offering class-leading performance for fast heat-up times according to Dynapac. The screed design is said to maximise paving quality and offers the ability to handle crown profiles from -2.5% to +4.5%.
The firm has installed special hydraulic push rollers that minimise bumping from a truck and allow all types of tipper vehicles to unload into the paver hoppers. Meanwhile the risk of cold spots forming in the hoppers is minimised while a large chain, wide throat and specially designed augers also help minimise the risk of material segragation. Sophisticated Moba paving controls are offered with the pavers, ensuring high quality performance.
Aimed at the US paving market, the VT LeeBoy's B series range now includes three conveyor-style models designed for a range of applications. The machines feature a sophisticated hydraulic control system as well as LeeBoy's advanced Legend Screed System. According to the firm, the three model B Series line offers high paving quality, efficient production, as well as being easy to operate.
Designed for the US paving market, the new LeeBoy pavers come with an array of options
With a 7tonne capacity hopper, the 8500B offers the choice of a 50kW Kubota diesel or a 47kW Caterpillar engine. Both the 8510B and 8515B have a 7.5tonne capacity hopper, and are offered with the choice of a 63kW Kubota diesel or a 62kW Caterpillar engine. The B Series pavers feature LeeBoy's Legend Screed System, which is said to provide high mat quality for paving widths of 330mm - 4.5m.
The system includes hydraulic screed extensions that can adjust to deliver smooth mats, while dual vibrators further eliminate seams. Each paver is equipped with two 914mm wide automatic conveyors, while the screed's wear plate is made with abrasion-resistant Hardox 450 steel for increased durability.
An efficient hydraulic system controls each paver, and can be easily operated with just one touch. Each model is driven by hydrostatically-powered tracks through a planetary drive system with variable two-speed torque hubs and internal brakes for continuous power and smooth operation. Maintenance and cleaning are simplified due to a hydraulically-raised hopper bed, while the 8515B also offers a self-cleaning crawler track system.
The pavers are available with high or low-deck options and the 8510B and 8515B have a night operating light package that is optional on the 8500B. A poly pad track, standard on the 8510B and 8515B, is available on the 8500B, while the 8510B and 8515B have the option of a continuous rubber track system.