Innovation in asphalt paving solutions

This year has seen a wide array of innovative additions to the asphalt paving market - Mike Woof reports

The worldwide asphalt paving market is both competitive and complex, with an array of important players jostling for position. At the same time, paving controls have taken a great leap forward with the development of accurate 3D systems that can use a combination of laser and GPS positioning. Leica Geosystems, 342 Topcon and 2122 Trimble have all introduced new packages for the asphalt paving sector and these are starting to be used on a number of key projects, offering similar benefits to the 3D machine control systems already seen in the concrete paving and earthmoving sectors for example.

Meanwhile the paving equipment machine market is broadly split into two technologies, developed in Europe and North America, with the former featuring tamper bar screeds that deliver pre-compaction and the latter using screeds aimed at high production throughput. 178 Caterpillar has long offered both European and US ranges, while 2394 Volvo's acquisition of Ingersoll Rand's road equipment line similarly brought both the European ABG and US Blaw Knox technologies. In recent years many European paver manufacturers with tamper bar technology such as 172 Bomag, 206 Dynapac and Vögele have made serious moves to develop high production machines for the US market. And now, a number of US paver firms are looking to design tamper bar screeds that will allow them to widen their global sales offering.

For example, 717 Leeboy is working on a European style tamper bar screed at present and while a launch date has yet to be announced, the firm has made no secret of its plans to introduce this unit as an option. The move is designed to boost its sales and presence in the paving markets outside of the US, while the company has also benefited from its manufacturing tie-up with Volvo for US pavers. Screed manufacturer Carlson is a dominant player in the US market, with its products fitted or offered as an option by most manufacturers, even including some firms making their own units. The fact that the firm is working on a European style tamper bar screed is of great significance. While Carlson will offer this to all manufacturers, it will be of particular benefit to Roadtec, a sister company within the 1250 Astec Group. As 1252 Roadtec has a notable presence in the Australian market, perhaps the only world market where both European tamper bar screeds and US style high production screeds are used, Roadtec's customers will be able to benefit enormously. 1222 Terex Roadbuilding also fits screeds from Carlson to some of its machines and as with Roadtec, the availability of a tamper bar unit would broaden this manufacturer's global presence also.

This year has seen major developments in terms of new products, with numerous manufacturers developing innovative machines. At the 688 Bauma exhibition in Germany 6791 Ammann unveiled its comprehensive paver line, recently acquired from Italian firm Antec and which now complements the firm's existing compaction range. BOMAG's key launch was for a wheeled version of its BF300 model, which shares features with the recently launched BF600 and BF691 models. Caterpillar's AP555E is designed for high mobility, with easy transportation and fast set-up times, while delivering high performance. Dynapac now has a more versatile version of its twin layer paving solution, which can also be used in more conventional applications by simply removing the specialist units, while the firm is also planning to introduce a new 2.5m class tracked paver. Roadtec's CP-90 is a more compact machine from the firm, which has previously focussed on larger pavers. Vögele's flagship Super 3000-2 paver, designed for major highway building projects, also attracted attention at bauma as this is by far the largest machine in the firm's line-up and is also said to be the largest paver currently available worldwide. Another interesting development was the arrival of the Japanese-built Sumitomo paver range to Europe through Yuasa Trading. The HA60C is a 2.3m class machine and the first of three tracked models to arrive, with wheeled pavers due in 2011.Since bauma a number of other market developments have occurred. UK firm 2526 BG Pavers is updating its line-up with new models that offer higher performance. The new C17 is a tracked paver with power from a 140kW 257 John Deere engine as standard although a 201 Deutz diesel with the same rating is also offered as an option and both engines meet current emissions regulations. With its standard HDTV25-50 hydraulic extending screed, widths of 2.5-9m can be paved although mechanical extensions allow maximum paving widths of up to 9m. However a wider HDTV30-60 screed option is available offering hydraulic extension from 3-6m and maximum widths with mechanical extensions of 10m. Electric heating is standard for both screed models although customers can select gas heating as an option if required. Transport width for the C17 is 2.5m and in operating use it is 3.2m wide (not including the screed). Depending on the specification the machine weighs from 17-20tonnes unladen and can deliver a maximum throughput of 720tonnes/hour. A wheeled version of the C17, the 317, is also available and this shares many basic specifications such as screed options and engines, although its paving widths are slightly narrower and its throughput is 700tonnes/hour. The operator station on the C17 and 317 has been designed for maximum visibility of the screed and hopper. The seat has an electric motor that allows the operator to move the seating position from one side of the deck to the other for the best visibility in any given operation.

The company also offers the 312 wheeled model, a mid-small size paver that weighs 13.2tonnes and can deliver 420tonnes/hour. Power comes from a JCB diesel delivering 85kW and this machine offers paving widths of 2.5-5m and up to 7m with mechanical extensions. Meanwhile the compact 308 wheeled machine has a 255 JCB diesel rated at 63kW, a maximum throughput of 180tonnes/hour and offers paving widths from 1.8-3.5m and up to 4m with mechanical extensions.

Vögele has made key model introductions to its paver range in 2010, both at the top of the line-up with its powerful Super 3000-2 and with its new compact machine, the Super 700. Taking the place of the Super 600 launched in 2006, the new Super 700 retains the compact dimensions of its predecessor, but has been improved. Power now comes from a Deutz diesel delivering 45kW while maximum paving width has been increased to 3.2m and it offers a maximum output of 200tonnes/hour. The machine can be operated in narrow working applications as it has a track width of just 1.1m, allowing a clearance width of 1.2m, while it also has an asymmetrical material hopper. With its compact dimensions the Super 700 suits jobs such as paving over backfilled trenches or repairs to minor roads and parking areas. As it has a low emission engine, the Super 700 can also be used for paving in underground or multi-storey car parks.

The machine is fitted with Vögele's AB200V extending screed, which is equipped with vibrators and has been specially designed for use with this paver model. When retracted the screed is 1.1m wide and extends hydraulically up to 2m, while bolt-on extensions allow a maximum paving width of 3.2m. For jobs such as covering over trenches, a novel paving width reduction system allows the machine to lay an asphalt mat just 0.5m wide. The operator can reduce the pave width to any size from 1.1-0.5m, while as the screed floats on the mix in this narrow working configuration, the firm says that optimum pre-compaction can be achieved. Like the larger screeds in the Vögele range the AB200V features electric heating that is said to deliver uniform heat distribution across the centre screed plates, the extending units and bolt-on extensions.