New asphalt paving innovations from around the globe
First publishedin World Highways
Two pavers and a material transfer vehicle are needed for the InLine paving system
Asphalt paving equipment manufacturers from around the globe are rolling out new and improved machines - Mike Woof writes
The pace of development within asphalt paving technology is quick, with new machines being unveiled all around the world. Machine manufacturers in Europe, China and Japan have been re ning and developing their technologies, which are aimed at differing global markets.
Two in one
German frim rm Vögele is part of the Wirtgen Group and has developed a dominant position in the global market, with its tamper bar models proving highly successful internationally. One of the firm’s important developments has been for a dual layer paving system, which it calls InLine Paving. This is designed to lay two layers of asphalt at the same time, hot on top of hot and providing a strong interlocking bond between the two that helps to boost pavement life. The method also eliminates the need for an emulsion layer in between the binder course and wearing course, and coupled with the ability to use a thin wearing course successfully this helps to lower overall materials costs for a paving project. Two pavers are used for this method, as well as a material feeder. The feeder provides the mix to the pavers, with the first machine laying the binder course and the second paver following immediately behind and laying the wearing course.
The firm claims that its Dash 3 generation for the InLine Pave system offers further benefits over the earlier machines. According to Vögele, the Dash 3 generation benefits from the new transfer module, for conveying the surface course mix to the downstream paver. This module has been extended by 1m. As with the MT 3000-2i material feeder, it has a diesel heater that ensures the mix remains at a constant temperature, preventing material from sticking to the conveyor. Another new feature is a second paver operator platform that has height-adjustable seats which can be swung through 90° over the side of the paver. The functions of the material transfer machine can be controlled from the second paver platform using the firm‘s ErgoPlus 3 console. Two cameras are fitted that can be mounted anywhere on the equipment so as to provide a good view of the operation and help boost
LiuGong's latest paver design offers improved performance
productivity as well as safety. In addition, the firm has simplified the steps needed to disengage the transfer module when it is not required, so as to allow the paver to be used for conventional paving operations. The other paver and the material transfer vehicle can also be used for standard paving operations. A camera system is also fitted to the hopper of the SUPER 1800-3i paver, used for laying the wearing course. The cameras provide a better view of the hopper, allowing the operator to prevent bottlenecks in material supply. As with the earlier versions of the wearing course paver, the SUPER 1800-3i is equipped with a water spray system that prevents material from sticking to the 400mmwide tracks.
The equipment has already been used on its first operations in Germany, with one job being to repair the B9 route. This busy stretch of road needed an upgrade as heavy traffic volumes has resulted in in excessive wear of the surface layers.
Using the hot-on-hot paving process for the binder course and wearing course offered the chance to lay new surfaces that would cope better with the route’s heavy traffic volumes. The construction team used a mobile MT 3000-2i Offset PowerFeeder, a SUPER 2100-3i IP paver for the binder course and a SUPER 1800-3i paver for the wearing course. The pavers are modified to ensure that they can deliver the InLine paving operation successfully. A special high compaction AB 600 TP2 Plus Extending Screed is fitted to the paver laying the binder course, so as to ensure that this can be driven over by the paver laying the surface course. Only then can the two be compacted using a roller.
Using the InLine Pave system ensures that the binder and surface courses interlock effectively for a high-quality bond, allowing the surface course thickness to be reduced to just 20-25mm. Once compaction is complete, the dual paving system is said to have fewer air voids and the surface course has greater resistance to water as well as deformation when carrying heavy loads in hot summer months.
Sumitomo pavers have been used successfully in key Indonesian airport runway applications
Chinese paving advances
LiuGong is offering an improved paver in the shape of its CLG509E model, which weighs in at 25.34tonnes. This machine can be used for paving asphalt base, binder and wearing courses as well as for underlying base layers. The paver is powered by a high torque diesel delivering 158kW that meets the China Stage III emissions requirements and which is electronically controlled. Other emission certifications will be available later. An ECO mode and automatic idling function are fitted, which the firm claims further boosts fuel efficiency by over 12% compared with the model being replaced. The machine features digital CANbus technology and the paving control system is said to minimise material segregation while the screed auxiliary control ensures optimum paving smoothness. Maximum capacity is said to be 900tonnes/ hour. The screed extends hydraulically and features a sophisticated heating system that reaches working temperatures quickly. The low front of the 16tonne capacity hopper optimises loading and the machine has pushrollers to minimise truck impact.
From Zoomlion comes the improved ZP3880RE paver, which is equipped with the firm’s RE90TV scree. The firm says that the ZP3880RE is highly versatile and its screed features a fast-heating electric heating system as standard, although gas heating is available if required. The screed can reach working temperatures in 30 minutes, has a single tamper bar and offers hydraulic extension from 3-5.8m. The auger drive system is centrally-mounted and designed to minimise material segregation, while the raised twin motors and drivechains allow access for maintenance.
The machine is driven by a Deutz diesel delivering 175kW and which meets the China Stage III emissions requirements. Maximum throughput is 900tonnes/hour, a major gain from the 600tonnes/hour capacity of the firms earlier top-of-the-range paver. The ZP3880RE has a hopper capacity of 18tonnes and Zoomlion says that the new screed and paver control system it has developed offers a high degree of working precision.
Zoomlion claims increased throughput for its latest top-of-the-range paver
Asian airport paving
Sumitomo says that it is developing a strong market share in Asian countries, in addition to its commanding position in the Japanese market. The latest versions of the HA60 and HA90 models are being utilised in an array of road and runway paving applications, with the firm having had particular success with the latter in the Asian market.
The Sumitomo pavers were utilised successfully at the Pekanbaru Airport runway repaving project in Indonesia. The work was carried out in 2015 and involved extending the runway with an additional 360m-long by 45mwide section. Sumitomo HA90C-2 pavers have also been used at Surabaya Airport and Bandung Airport, using screeds set at 7.5m and 9m wide respectively. The company claims that its machines are able to give a higher quality finish for the wearing course than many competing machines, which is said to be of particular importance for aircraft runways. Because of the severe stress loads exerted by aircraft landings in particular, runway finish and structural strength are key issues. In some airport runway applications in Asia, echelon paving is being carried out with two or more pavers operating in tandem to deliver a durable hot-to-hot joint that is longer lasting and more resistant.