New asphalt paving technologies boost performance

Sophisticated new paving technologies are coming to market that will help boost quality and performance

New paving technologies are being introduced to meet the differing demands of both North American and European customers. Although North American and European paving techniques do vary, there are also some control technologies being introduced that will help quality for both approaches.

Designed to meet European paving needs, 172 Bomag's new BF300 paver is said to be a combination of the best German and Italian engineering and shares a number of features with the larger BF600 launched during last year. The more compact BF300 is aimed at the 7-8tonne class and is designed to be versatile and manoeuvrable, featuring a transport width of just 2.5m. The BF300 replaces the wheeled and gas-heated BF331 model and this new design comes with a choice of wheels or tracks as well as gas or electric screed heating. With this screed, pre-compaction of 88-91% can be achieved according to BOMAG. The new screed can extend hydraulically from 1.7-3.4m and offers a maximum width of 4m using side plates. The electric version has moulded heat elements that are said to allow better heat distribution as well as reducing corrosion of the heating rods and can reach optimum operating temperatures from cold in just 20-30 minutes. The 4.8m3 capacity hopper features scraper belts, auger drives and bin flaps that are individually controllable. An Ecomode package is fitted to the engine management system that governs the emissions compliant 1265 Kubota diesel powering the BF300 machines, helping to reduce fuel consumption and optimise performance. The hydraulic system is also configured so as to improve efficiency and reduce fuel consumption with ancillary pumps instead of flow dividers. Other features include ease of operation, good visibility due to the low-profile engine mounting and side-slew operator platform and ease of operation.

Designed for North American paving needs, the latest 717 Leeboy machines offer high performance and quality according to the firm. LeeBoy fits its own electric screeds to its pavers although the firm previously fitted 2599 Carlson screeds and can offer these if specified by the customer. The new 8816B tracked paver from Leeboy offers improved performance over the previous model and is also easier to service and maintain. Mark Bollick, service & warranty manager for LeeBoy said, "We went to a Canbus control system and this gives us a digital display for fault codes."

The revised joystick steering, sealed touchpad screed controls and new auger controls make the machine easier and more precise to operate. The sliding seat can be positioned over the side of the machine allowing a better view of the screed, while the operator also has an unobstructed view of the hopper for loading. Power comes from a Tier 3 rated 196 Cummins diesel and other features include a new parking brake.

He said that the firm's 9000 wheeled paver is versatile and productive and also features LeeBoy's own electric screed as standard. He said, "It's a rubber tyred machine with front wheel assist and power from a 130kW 178 Caterpillar engine that meets Tier 3 emission requirements."

The slide out console and slide out seat can be positioned as required by the operator to provide a good view of the screed. As with the 8816B, the 9000 features touchpad controls and Canbus electrics, allowing separate operation of augers, conveyors and other functions. The electric screed can pave to a width of 4.72m using hydraulic extension and up to 6.1m using bolt-on extensions. The 355.6mm diameter augers can be raised for loading and unloading and the machine features a hopper capacity of 11tonnes.

Suitable for use with both North American and European style pavers, the sophisticated paving control system from German firm 1228 MOBA can make a significant improvement to paving quality.  The unit monitors the heat spread of the mat behind the paver, using an array of sensors to scan the temperature gradient right across the screed every 50mm. An array of infra-red cameras look straight down on the mat and tracks how the machine is operating and identify and cold spots, allowing the paver operator to adjust the screed, augers or other controls accordingly to ensure a homogenous spread of material. Because the system logs GPS co-ordinates it can identify cold spots where trucks have stopped and if necessary, these can be milled out and replaced. The benefit to the user is that areas of the mat that are too cold for proper compaction can be addressed early on, ensuring that there are no air voids and preventing subsequent water ingress that can lead to potholes forming.
The standard sensor beam features 12 sensors but up to 24 can be fitted if required. A colour touch screen is fitted that shows the paver operator the heat image of the mat as it is paved and the system can record data onto USB sticks or a PC for later analysis. In addition, a GPS receiver and antenna are part of the package to provide accurate location data. The system comes with Moba's own software and can be fitted to any type of paver.

1222 Terex says that its CR662RM material transfer vehicle offers a versatile alternative to other machines designed for this purpose, while also helping to ensure an even mat temperature and reduce material segregation. Unlike rival units, the Terex machine can also be fitted with a screed and this increases its utilisation. As standard the machine can be fitted with a Stretch 20 screed with diesel or electric heating, the Fastach 10 screed with diesel or electric heating or the electric VersaScreed 210. Because the machine runs on tracks rather than wheels, it features a lower ground pressure and can operate in more difficult working conditions according to the firm. The17.9tonne CR662RM offers a maximum throughput of 544tonnes/hour and weighs 24tonnes when fitted with the conveyor assembly and 22tonnes when equipped with the Stretch 20 screed. Its hopper capacity is 7.56m3 and load capacity is 34.5tonnes as standard, although a special hopper insert can increase load capacity to 39tonnes. Power comes from a Cummins QSB6.7 diesel delivering 194kW that meets the Tier 3 emission requirements.

2122 Trimble hopes to build market share in the market segment for asphalt highway construction techniques with its latest paving control technology. The new system was launched earlier this year at the Trimble Dimensions event in Las Vegas. Hot off beta testing, the new PCS400 Paving Control System is an automatic screed control system that improves accuracy and productivity in asphalt paving, and minimises asphalt waste. Feedback from companies involved in the PCS400 beta test, such as WG Yates, which presented a session at Trimble Dimensions on asphalt paving productivity, was very positive.

The introduction of the PCS400 is a strategic move that puts Trimble, "...back in the game," in the paving market, according to Arthur Taylor, segment manager in Trimble's heavy & highway construction division.

Jeroen Snoeck, segment manager for Trimble's paving construction division, made it clear that the PCS400 is designed to work with any machine and the system was displayed in the exhibition hall at Trimble Dimensions on a 2394 Volvo PS6110 tracked unit, while the off-site demonstration featured an installation of the PCS400 on a Caterpillar AP655 tracked paver. The installations both featured single sonic on one side and averaging beam on the other side, with a slope sensor.

This non-contact control system features five sonic sensors/tracer, so as to average out smaller irregularities. Meanwhile the averaging beam features three ST200 Sonic tracers so as to average out longer irregularities in the surface.

Volvo is building on its high quality screed range with the introduction of the new Ultimat 200 model, which is offered as an option for the firm's PF6000 pavers along with the existing Omni 318 and Omni 1000 screeds. The Ultimat 200 is a versatile front-mounted vibratory screed offering standard paving widths of 3.05-6.1m and fitted with electric heating as standard. While sharing features with the existing Omni models, the new Ultimat 200 offers a novel double extension system and a heavy-duty mainframe for longer life. Vibration speeds of 17-42Hz are achieved by the new Ultima 200 while revised controls make the unit easier to use with single button operation of extension, as well as automatic control of slope, grade and heater elements. Innovative heat bar technology is said to provide uniform heat to the screed, improving mat quality and reducing screed plate distortion. Three heat bars are fitted/section and these units are interchangeable and can be replaced without removing the screed plates for ease of maintenance. Thermal insulation prevents heat loss into the frame, boosting performance.

All three screeds can be fitted to the tracked PF6110 model as well as the wheeled PF6160 and 6170 models.