A modular design allows the dowel bar inserter for Wirtgen's SP500 to be extended to a width of 6m and this system can place dowel bars with a maximum diameter of 4mm and a maximum length of 600mm
The concrete paving market has provided stable ground for existing players, though key market developments are in hand
US manufacturers have long dominated the concrete paving sector with well-known firms such asOther parts of the equipment market have to contend with issues over copying of designs. But in concrete paving, the prospect of a Far Eastern manufacturer for example presenting a truly competitive machine in the near-mid term is extremely slim and even in the long term, this seems unlikely. Because concrete paving is a comparatively niche market with established players, entering the sector with a rival design would present a significant challenge and given the comparatively limited volume, the commercial prospects would not be large while the risks would be high. Some Far Eastern firms have attempted to copy proven concrete paver designs from established manufacturers but these have so far been less than successful. The fact that concrete slipforming entails considerably more than just the machine means that simply building a piece of equipment that resembles a proven unit does not guarantee success. Building a durable, productive and reliable concrete paver entails an understanding of materials technology and how steels cope when in contact with abrasive concrete. At the same time the designer of a concrete paving machine has to comprehend the behaviour of the concrete itself during the slipforming process.
As a result the real competition is coming from within the existing players. Earlier this year Wirtgen announced its intention to enter the US market, with models developed specially for North American users. And more recently Guntert & Zimmerman has revealed that it is developing a more compact machine than its previous designs, having focussed in previous years on extremely large pavers for applications such as canal construction.
Both of these moves are of note. Wirtgen is a European manufacturer entering the home of the concrete paver. Guntert & Zimmerman directly into competition with the other firms building machines aimed primarily at road construction applications.
Guntert & Zimmerman says that its new S600 offers high manoeuvrability and versatility to suit a wide array of paving duties. The machine is designed to pave widths from 2-8m. The manoeuvrability is achieved due to its 90º steering while the machine features rollers and hydraulic clamping pucks that are said to eliminate the need for bolted adjusted clamping plates. This feature also allows the user to camber the frame to remove sag at greater working widths.
The swing legs and rotary actuated track steering work together so that the crawler tracks automatically adjust to the forwards position. The machine can also be set to the 90º steering mode and features a transport mode and once selected it will set itself semi-automatically. According to the firm the new S600 can offer all the performance parameters of its nearest rivals while providing high reliability of all key components. The S600 is designed to be highly durable according to Guntert & Zimmerman and the firm claims that the unit's jacking columns are more rugged than most of its nearest rivals. The company has used much larger section square tubes and larger diameter cylinders (with 1.67m of hydraulic lift) to allow it to handle higher barrier molds as well as a dowel bar inserter.
The paving kit can be cantilevered in one of two ways, either being hung off the end of the tractor frame while it is in the paving mode, or cantilevered off the centre of the tractor frame while the tracks are turned 90º in transport mode. Power for the S600 comes from a fully-enclosed and noise insulated
The customer for the first machine is in the US with orders for two more units in hand and due for delivery shortly.
Guntert & Zimmerman is offering novel telescopic end units, which are designed to be fitted to the S600 and raise total working weight to 32tonnes when installed. These units allow contractors to change slipforming quickly, while also meeting tight smoothness specifications. The firm's new telescopic end sections allow a contractor to change width by 1.8m and according to Guntert & Zimmerman, width changes that would normally take a four person crew a working shift can now be carried out by 1-2 site personnel in two hours. These end sections can also be specified as an option for new S850 or S1500 models or can be retrofitted to existing machines.The firm is also offering a new remote control that allows the equipment operator to control one set of tracks from the ground level. Called the Walk Box, this unit gives the operator the ability from the ground to move the left or right tracks in or out to perform width changes. An operator can use the unit to slowly and accurately move a side of the machine without climbing onboard to use the operator console. This unit is offered on the G&Z S600, S850, S1500, PS1200, and TC1500. This innovative product runs on a single AA battery and connects to the machine's track pump through a standard four pin connector.
Wirtgen's SP15 and SP25 slipformers are developed for the US market and will be equipped with trimmers, to meet the needs of North American contractors. The SP15 and SP25 are versatile machines for laying kerb and gutter, barrier, sidewalk, V-ditch, special applications and slabs and both can be configured on-site for left- or right-side pouring. The compact SP15 has a maximum paving width of 1.8m for offset applications, maximum kerb/parapet placement height of 1.295m, and weighs 13tonnes with trimmer, auger conveyor plus kerb and gutter mold. The SP25 has a maximum paving width of 3.5m, maximum kerb/parapet placement height of 1.8m and weighs 18tonnes. Both units are modular in design and can be fitted with either three or four tracks.
Wirtgen has also developed new dowel bar inserters for its slipform pavers and this is now offered as an option across its 10 model range. The Wirtgen concrete paver models offer standard working widths from 1-16m and are said to feature state-of-the-art technology, with versatility being increased due to the availability of the improved dowel bar inserter.
The new dowel bar inserters are designed for precision and versatility. The units place dowel bars into the concrete longitudinally, using high-frequency electric vibrators and with a hydraulically controlled, vertical movement. This system is said to ensure that dowel bars are inserted correctly across the entire working width.
The dowel bar inserters can be specified in standard dimensions or custom-made to a client's specification, versatility achieved due to the modular design. The standard model can work with dowel bar lengths of 450-600mm and diameters from 25-40mm. A novel feature is that the base plates and maintenance-free feed are fully movable, including the vibrating frame and vibrating needles. This allows conversion of the dowel bar inserter in case of varying dowel bar spacings, which maximise paver. When altering the dowel bar spacing, a user can adjust the system easily due to the movable base plates and vibrating needles. Meanwhile the dowel bar inserter and finishing beam are available in a novel package that is said to ensure that the paved slab will be smoothed after dowel bar insertion, eliminating the need for a second mold.Despite the competitive moves being made by Guntert & Zimmerman and Wirtgen, GOMACO is in no mood to relinquish its strong position in the concrete paving sector and continues to develop new variants of its machines that deliver additional versatility for the user. The firm's highly successful compact machines including the GT-3400, GT-3600 and Commander III models in particular have seen a range of upgrades and additional features. Most recently the firm added further functionality to its well-proven Commander III model with the four track model now being offered with the additional option of both right and left hand pour capabilities. This feature was first offered on the firm's GT-3400, effectively by allowing the user to turn the machine through 180º, and is now available as an option for the Commander III as well.
GOMACO's most recent machine addition to its option line-up has been the development of a sophisticated independent dowel bar inserter (IDBI) system. The IDBI was initially designed to operate with just one of the firm's range but can now be fitted to all of the larger pavers. Because the IDBI is a large and productive unit in its own right it has its own power source, however it is designed to integrate fully with paver to which it is attached. The IDBI's electronic controls plug in directly to the control system of the paver with a CAN cable connecting the controllers. This allows the operator to run both machines together, effectively as a single unit as the two systems communicate with each other and function with simultaneous operation and response to control commands. When the operator stops the paver, the linked controls mean that IDBI's tamper bar and screed will turn off automatically and when the operator restarts paving, the IDBI also restarts working automatically.
GOMACO has developed the IDBI and the system is now able to handle great widths of up to 2.88m. The IDBI is powered by a Tier 3/StageIIIA compliant,
To allow the user to attach or remove the IDBI quickly and easily as required, this system is equipped with its own outriggers that speed attachment to the paver and also make it easier for loading and unloading the unit for transport. These outriggers reduce set-up times and maximise utilisation.Increased versatility is also a feature of the new Max Package that Power Curbers has developed for its well-proven 5700-C slipformer. In the past the 5700 class machine was limited in terms of the size of mold it could use, however the frame has been strengthened and the legs repositioned to make it rugged enough and sufficiently stable. Longer, heavy duty tracks have been specified along with low speed torque hubs on the crawlers for precision tracking at the low speeds required for applications such as centrelane barrier work. Meanwhile stability is maximised as the right crawler has been moved forward.
These modifications allow the machine to pave widths of up to 3.65m and barriers up to 2.4m high, a significant increase from earlier generation versions of the 5700. But despite the changes to the machine that allow it to carry much molds, the 5700-C Max can be reconfigured to a more conventional specification. The right leg can be moves back in its standard mounting position, while like some of the other recent 5700-C models, this new variant can also be set up to handle right as well as left side pours.
Power Curbers built a special mold for a UK customer with a high degree of adjustability designing sides that can be raised hydraulically to suit concrete concrete barrier work. The mold also has a channel in the top that leaves space for the electrical cables used to power the lighting mounted on top of the barrier. As the mold weighs 4.5tonnes the right leg of the machine has been moved forward by 1.2m and there is also a counterweight fitted, with these features boosting stability.
At Terex Roadbuilding the emphasis has been on developing the Oklahoma manufacturing facility, allowing it to respond faster to the needs of the market. The Oklahoma City facility makes both asphalt and concrete roadbuilding equipment; asphalt pavers, reclaimer/stabilisers, milling machines, kerb and barrier machines, and plants. The facility has been retooled to be more agile and more focused on its customers and the firm is also investing in new product development. New machines and options are planned and it seems likely that Terex Roadbuilding will add new options to its concrete slipforming line, perhaps with new variants to suit a wider array of barrier work as well as sophisticated dowel bar insertion options. Terex Roadbuilding is also running new dealer and contractor classes at the Oklahoma City training centre with revamped asphalt and concrete courses offered through the Terex Roadbuilding University.
With regard to training though it is worth noting that GOMACO has been carrying out extensive operations for improving the skills and abilities of concrete paving crews over many years. The GOMACO University runs regular courses at the Ida Grove facility, with many contractors returning regularly to refresh their skills and learn the use of new generation tools such as the use of stringless paving techniques. Power Curbers has also implemented a training programme for users while Wirtgen is also offering concrete slipform paving manuals in English, French, German and Spanish. Part 1 of Wirtgen's paving manual series is aimed at offset application and paving concrete slabs and is called: kerb, barrier, sidewalk and multipurpose applications. This focuses on the firm's smaller pavers, the SP150, SP250 and SP500. These manuals have 223 illustrated pages and provide tips for conventional paving situations.
