Asphalt paving advances Competition is increasingly fierce in the asphalt paving market - Mike Woof reports
With the asphalt paving segment split broadly into two methods, American or European, it is no surprise that manufacturers. from these countries have dominated the market for some years.An interesting development in recent times has been seen with various European firms developing asphalt pavers to suit North American needs, including
The pace of model development has been rapid, while various firms have also been expanding product lines or even acquiring model ranges. For 2012 several firms will be offering new pavers, with many of these models making their first public appearance at the
These are hydrostatically driven machines running on wheels and tracks respectively and offering paving widths from 1.8-3.5m and the output potential of up to 230tonnes/hour. A wide range of optional equipment is available including either vibratory or tamping/vibratory screeds and with the choice of gas or electric heating, as well as automatic lighting and temperature control functions.
Weighing in at 20.2tonnes, it is offered with either the Cat C7.1 or C6.6 diesels, depending on customer requirements, while it offers standard paving widths of 3.05- 5.94m. Other features include dual operating stations, tilting consoles, a choice of rubber tracked undercarriage or wheels, high ambient temperature cooling, an option of 25 kW or 35kW generators, and a special material handling system with independent auger and conveyor controls. Meanwhile the compact AP255E is designed for use by a single operator and for small and medium sized jobsites in urban areas as well as trench back filling and maintenance and repair. Highly manoeuvrable, the AP255E is powered by a Cat C2.2 engine, weighs 4.5tonnes and offers standard paving widths of 1.4-2.6m. Its AS3143 electric screed is powered by an on-board generator with independent temperature control in all four sections. Three heating elements for each screed section ensure uniform heating over the entire screed plate.
Roadtec is addressing the needs of US customers with its new 3m class asphalt paver models, which have been extensively redesigned. These are now available with Tier 4 Interim emission control technology in the shape of a 168kW Caterpillar C7.1 diesel, as well as an array of other upgrades and improvements. The new e-Series pavers are the rubber tyred RP-190e and the tracked RP-195e models, which are designed for sale into North America where the latest emissions legislation is in force. However Roadtec is also offering versions of these pavers with similar power outputs for certain export markets that do not have the Tier 4 Interim standards and these can be recognised by the designation 'ex' after the model number.
The firm says its new pavers offer improved operator visibility and easier access to service points, as well as redesigned operator stations that provide more comfort and are equipped with hydraulic-pivot consoles and selectable seat positions. Among the numerous performance upgrades are new adjustable delta plate design, redesigned hydraulic tunnel panels for improved accessibility, and increased fuel capacity from 454-511litres.
The conveyor chains are now beefed up with the use of heavy-duty offset types, while the floor plates are made from wear resistant chromium carbide and drop in without bolts.
A new dual hinge apron plate design allows access for cleaning, while access to hydraulic filters and test ports has been improved by clustering these components in one location. Meanwhile release agent spray-down systems are now standard and include a dual system; one for diesel, the other for release agent.
In addition Roadtec is introducing the new E-Series of its Shuttle Buggy MTV. Amongst the improvements are improved conveyor wear resistance and dual operator stations, which can slide past the outer edge of the main frame, improving visibility. Mix storage has been improved with the addition of indicators, which show how much material remains in the hopper. An optional, adjustable width front dump hopper is offered to accommodate different widths asphalt mix haul trucks. Power comes from a Caterpillar diesel rated at 224kW and which meets the Tier 4 Interim/Stage IIIB emissions legislation.
The new SAP90EC paver from Sany represents a major step ahead for the firm, with drive from a new generation Deutz diesel that features low working noise, electronic engine management, automatic power control and an economy mode that can cut fuel consumption by up to 15%. Effective cooling allows the paver to operate in ambient temperatures of up to 50°C. The machine has a large 8.5m3 hopper and large conveyors, which helps optimise material delivery to the screed, while a sophisticated hydraulic system is said to maximise operating efficiency. The adjustable augers feature a large pitch and large diameter blades, which is said to ensure good material distribution and to prevent material segregation after paving. This 24tonne paver offers paving widths from 3-9m and its screed has a single tamper bar as well as vibration, while the machine is also said to deliver a smooth finish.
Sumitomo's new asphalt screed is said to offer wider extension than other designs on the market at present, increasing versatility for the contractor. The firm says that this screed can be extended to 2.5 times its minimum width, compared with twice the width for other existing models available.
This special telescoping system allows a paver to be feature a more compact width for use in restricted areas than other machines with a similar maximum width. The 2360 model offers a maximum paving width of 6m while it can be retracted to a width of 2.3m, compared with 2.5m for a conventional design. Meanwhile the larger 3075 model can be extended hydraulically from 3-7.5m.
For both units this has been achieved by mounting the extending screed sections to the front and rear of the central unit, rather than side by side as in a conventional design.
The novel mounting allows the extending sections to telescope further than on standard screeds, providing greater versatility to the user. Bolt-on extensions can also be used as with conventional units, further increasing paving width for
Developed for the North American market, the
This layout reduces centerline segregation and eliminates the need for reversing augers and the centre gearbox drive found on competing pavers. The anti-segregation system further helps cut material and thermal segregation during paving, while the twin counter-rotating augers draw down material from all areas of the hopper and re-blend the asphalt to produce a more homogeneous mix. The design of the augers is said to pull material from directly above the full length of the shafts. The sloped auger design is said to allow a larger opening at the end of the feed tunnel, eliminating material build-up. The feed tunnel has a 2.4m long mixing zone under the engine compartment and the material is mixed in a figure of eight pattern by the pugmill-style mixers and is then fed to the spreading augers. The machine also features a three-point suspension system that helps maintain a consistent feed height at the screed for a smoother mat. Raising and lowering of the paver's rear frame also helps truck loading and unloading.
The standard hopper capacity of the CR652RX paver is 15tonnes although it can be increased to 24.5tonnes using the optional hopper extension. The machine is powered by a 191kW
German firm Vögele intends to maintain its position as one of the technological leaders in the asphalt paving market and is now introducing the first of its new generation machines. According to the firm, the Super 2100-3i paver is designed to raise paving efficiency to another level. This new machines features intelligent emissions control and is powered by a six-cylinder Cummins diesel, with a variable speed fan that provides sufficient cooling when required. Meanwhile its EcoPlus package is intended to help reduce fuel consumption and noise levels, with a switchable transfer gearbox that allows hydraulic pumps to be by-passed when they are not required.
The Super 2100-3i also comes with a revised operator platform and a larger colour display. The AutoSet system raises the hopper sides, folds up the hydraulic hopper front and also raises the deflectors in front of the tracks, the augers and the screed. When selected by the operator, this system allows the paver to be moved quickly and easily on the job site. An automatic docking function called PaveDock is another new feature that absorbs impacts from the feeder, while any lorry movements required during the feeding process are communicated to the lorry driver using a set of signals.
From Volvo comes the new P7820C ABG and P8820C ABG pavers, with independent travel drives and electronic traction control to maintain productivity on slopes and around corners. The P8820C ABG is a tracked machine and can pave up to 900tonnes/hour in a mat up to 13m wide, while the P7820C ABG paves up to 1,000tonnes/hour and a maximum mat width of 11m.
Both machines are powered by Volvo's latest D8 stage IIIB emissions compliant sixcylinder, 7litre diesel, rated at 175kW in the P7820C and 200kW in the P8820C. To help reduce fuel consumption the machines feature a smart power mode that lowers engine speed to match demand and can provide fuel savings of up to 30%. Meanwhile individual, electronically controlled track drives are said to ensure that straight line and fixed radius work remains accurate.