Innovation abounds at the smaller end of the compaction equipment sector

New machines are now being offered at the compact end of the asphalt compaction market - Mike Woof reports

Manufacturers have developed an array of new machines and solutions for the compact end of the asphalt compactor market segment. These units have been designed to meet the latest regulations for Europe and the US, with low emission engines that are also more economical on fuel. But as these machines are made in large volumes, the market for smaller asphalt compactors sees fierce rivalry between firms. A high percentage of machines at the smaller end of the asphalt compactor segment are aimed at customers with rental fleets and these companies are very price sensitive. As a result, manufacturers have a tough job in offering the high-quality, dependable products with low maintenance needs their customers want, but at the competitive prices the buyers are prepared to pay.

With the vibrating roller having originated in Germany, it is no surprise that the country is also one of the leading producers of compaction equipment in the shape of brands such as 172 Bomag, 206 Dynapac and 228 Hamm, as well as the Vibromax range acquired by 255 JCB a few years ago. With BOMAG and Hamm in particular, massive investment has seen both companies increase production capacity in Germany as well as in China, and also significant moves in new product development. With other major players in the sector such as 178 Caterpillar, Dynapac and 2394 Volvo also gearing up on factory capacity and introducing new products, the level of competition is particularly high.
BOMAG says that its new range of light tandem rollers offer high performance and feature the firm’s sophisticated Economizer system. This package allows the roller operator to monitor compaction status, with soft spots requiring additional passes being highlighted on the screen. Because assessing compaction is tricky with these smaller machines, operators often err on the side of caution and may carry out additional passes so as to make sure the surface has been compacted. However this takes additional time and fuel and also runs the risk of over-compaction in some instances.

The Economizer system is said to offer reliable results and ensure quality compaction, particularly for sites in urban areas where roller operators have previously had to make judgement calls on how many more passes may be required to bring the surface within the required tolerance. The display is located on the machine dashboard and shows compaction progress in real-time using an LED indicator. The system is said to be able to assess the load-bearing capacity of the surface being compacted and then shows this in the increasing number of yellow LEDs illuminated on the display. When the number of LEDs illuminated stops increasing, the compaction work is complete.

The Economizer can also detect weak spots in road sub-bases, when the number of LEDs illuminated will suddenly decrease. In addition, the risk of aggregate being crushed or of the roller bouncing when the surface is compacted is also indicated by a red LED lamp in the display. This signal ensures that the operator can prevent over-compaction and also avoid damage to the machine.

The Economizer package is now offered as an option for BOMAG’s fifth generation small compactors, ranging from the BW80 to the BW138. These machines are also powered by engines complying with the latest exhaust emission regulations.

Trench compaction

6791 Ammann has now started production of the infra-red controlled trench roller it launched earlier this year. The Rammax 1575 CI trench roller is an articulated model and is offered in addition to the proven, skid-steered 1585 unit, with which it shares a number of components. This new model is powered by a liquid-cooled, three cylinder 7139 Yanmar diesel, which is said to offer high output for efficient compaction, productivity and gradability while also being highly fuel efficient and meeting the latest emissions legislation. The model has a low centre of gravity and a novel articulated pendulum joint which combined to offer high stability even on difficult terrain. A key feature is its highly sophisticated, solar-powered remote control, which uses proven infra-red technology and has also benefited from a series of improvements and upgrades. The firm says that this technology allows the unit high safety standards for the operator and the surrounding site. The articulation system is said to allow tight turning for use in compact sites

Although best known for its line-up of earthmoving and quarrying machines, 176 Case is offering a Czech-built range of compactors in the US. The revised DV range is now taking the place of earlier models, with new features and increased performance. There are three compact models, the DV23, DV26 and DV36 which are all aimed at the rental market and weigh 2.25-2.45tonnes, 2.46-2.65tonnes and 3.74-4.3tonnes respectively. Key features include tight turning circles, an offset drum, high kerb clearances and soft starting and stopping functions.  “It has very good access to the engine and high manoeuvrability, with a 2” offset,” said a company spokesperson of the DV36. “We do have foldable ROPS so you can use the machines in low height conditions.”

The DV23 has 700mm diameter drums that are 1m wide, DV26 has 700m drums that are 1.2m wide and the DV36 has 850mm diameter drums that are 1.3m wide. The machines are powered by Tier 4 Interim compliant Yanmar engines rated at 23kW for the DV23 and DV26 and 30kW for the DV36. The power rating for the DV series means that there is no need for after-treatment, which helps lower maintenance needs.

Hamm has pioneered the oscillatory compaction system and is now offering this as an option for the compact asphalt roller segment, a technology previously only available on its medium and large asphalt twin drum asphalt compactors. The oscillatory compaction system is said to offer key benefits in certain applications such as in areas with structures nearby that could be affected by vibration or for bridge decks.
The HD CompactLine now comprises 16 models in all, the widest array of variants available on the market for asphalt compactors weighing up to 4.5tonnes according to the firm. With the construction of oscillatory rollers in this weight class, Hamm says it is responding to the increasing demands for high-quality compaction even in extremely small areas. Oscillation is said to increase compaction speed and quality and suits applications in urban areas for example. The advantage of the oscillation system is that it delivers a fast increase in compaction because the drum delivers direct tangential thrusting forces into the surface according to the firm. At the same time, the drum also remains constantly in contact with the ground. The combination of continuously acting static load and changing dynamic shear forces in the material are said to deliver faster and more efficient compaction of the surface.

Up to now, conventional compact tandem rollers have only been able to operate in static mode on narrow construction sites. However, the Hamm compact oscillatory rollers can work dynamically in these applications. This is because oscillatory compaction forces do not disturb buildings or pipework below the road surface through transmitted vibration. At the same time, the machines are also said to deliver a better compaction result, and quicker than can be achieved with conventional equipment.

In addition, the HD CompactLine range also includes the Hamm HD10C VT combi roller, which is the smallest combi roller in the line-up. This unit offers a working width of 1.06m and operating weight of 1.5tonnes and comes with permanent all-wheel drive as standard, as with the proven HD8 and HD10C tandem rollers. The machine is said to offer best-in-class gradeability in all applications.

Rubber tyred option

The latest Dynapac CP274 pneumatic tyred roller from 161 Atlas Copco Road Construction Equipment is said to be equipped with a spacious platform with operator-friendly controls, plus a rotating and sideways sliding seat and steering assembly. The cab is said to offer good all-round visibility and features either air conditioning or automatic climate control. The Dynapac CP274 rollers are powered by Tier 4 Interim/Stage IIIA-compliant engines, which offer reduced emissions as well as low levels of ambient noise due to thermostatically-controlled cooling fans. The quality of the finished surface is said to be improved by a smooth start/stop system when changing direction. A dual-circuit braking system maintains full braking effect even if one circuit is disabled. The machine is built on modular lines and shares many components and sub-systems with other models in the firm’s range. For users, this parts commonality results in cost savings in areas such as servicing and spares management. The Dynapac CP274 has a compacting width of 2.3m and a maximum operating weight of 27tonnes. It is ideally suited for a wide variety of finishing and sealing asphalt work, plus soil compaction applications. An optional DCA-A compaction analyser ensures the optimum number of passes when absolute accuracy is a must.