Laying in patterns – easier and more quickly
For handling block layers that are not flush, owing to the particular formation, the installation clamps are provided with adaptors that provide a good grip in the gaps without destabilizing the bond of the block layer. Layers that must be processed by older installation clamps having no such adaptors must be temporarily supplemented with half blocks. This is time-consuming and inefficient. To this problem, Probst has found a mechanical solution.
Pavers are delivered in packs of formatted block layers. With some formations, e.g. the herringbone bond, getting hold of the block layers poses no problems when concrete blocks are concerned. The special adaptors, with which the modern installation clamps can be equipped, hold the block layers in a firm grip. When laying pavers in a herringbone pattern problems do now and again arise. The reason for this is that clinker pavers are not as uniformly dimensioned as concrete blocks, with the result that the pressure of the clamps on the edges of the block layers is not always uniform. The block installation specialists from Probst have looked into these special problems and developed a solution: The installation clamps from Probst are now available with a special herringbone adaptor with which block layers in herringbone pattern can be safely and reliable gripped and installed.
Probst offers three types of hydraulic block clamps in its equipment program: HVZ, the HVZ-uni and the HVZ Genius. Common to all of these clamps is that they can be suspended from any lifting unit that is fitted with hydraulic connections, e.g.: hydraulic excavators, wheel loaders, stackers, loading cranes and, in particular, the two mobile installation machines VM 203 and VM 204 from Probst. The HVZ is, so to speak, the basic model of the clamp series from Probst. The HVZ-uni is a further development of the HVZ. This machine is not only more robust and universal in use than its predecessor, but can also be much easier adjusted to the block layers. In addition, there is the standard comfort equipment. The main and secondary spans can be easily adjusted via scales. The side clamps can be hydraulically folded up so that the block layers can be positioned closely to the limit areas (curbstones, walls etc.). The gripping depth can be quickly adjusted on the positioning rollers.
The automatic push-off device
Probst places great stock in the automatic push-off device ADV, which is standard equipment of every HVZ-uni. The installation clamp holds the block layer in a secure grip, supports it on the laying edge, pushes the block layer forward and, at the same time, releases a sudden heavy impact from above. The side grippers open up only after the block layer has been exactly positioned in the bedding by the two pressure applications. The application of pressure and the release of the clamps happens nearly simultaneously. The block layer lies in the sub-grade as if imprinted. No block can drift out of alignment or tilt. No manual reworking is required. The precise and uniform joint pattern of the completed pavement is impressive. This obviates the need for manual reworking with a rubber mallet.
The Probst top model for every type of excavator is the HVZ Genius. This special-purpose excavator attachment clamp is fitted with a hydro-mechanical control system, in addition to being equipped with all of the features of the HVZ-uni . With just one hydraulic control circuit and the fully automatically selectable motion sequences of the clamp, the HVZ-Genius can be put to many uses.
A hydraulic torque motor is just as part of the equipment of this clamp as is the universal excavator suspension device. The new herringbone adaptor of the Probst installation clamps equalize all irregularities along the edges of the block layers and make the installation of block layers in herringbone patterns simpler and easier.
Paving at the gate to the world
Gate to the world – The Hanseatic city of Hamburg owes its sobriquet to its port. The flow of containers has risen rapidly, particularly in recent years. By now, the storage and reloading points extend far into the hinterland of the port. At the end of July of this year, a new container storage area covering approximately 170,000 m² was completed. The client was the company Euro Gate. A block pavement made up of chamfered Supra blocks of 12 cm thickness had been specified as surfacing. The paving blocks required for this project were supplied by the concrete plant Betonwerk AHE, Rinteln, Germany. The contract for laying the in total six million paving blocks was awarded the experienced construction company of TS-Bau, Torsten Stengelmann, Bornhöved, Germany, via the general contractor Eggers, Tangstedt.
TS-Bau was naturally pleased to get the job. But since the deadlines set for completion were rather tight, the company had to upgrade its laying equipment. At TS-Bau, the decision fell on the VM 204 Robotec. This machine is provided with a heatable driver’s cab enclosed with all-around safety glass to facilitate work in winter. The machine operator does not have to pay attention to any “particularities,” malfunctions having been eliminated from the outset.
A robust, reliable PLC control system enables the machine operator to control from his cabin the motion sequences of the hydraulic installation clamp manually, semi-automatically or – following activation of the appropriate presetting switches – fully automatically. In automatic programming mode, the program sequence can be changed at any time. When the block layer, for example, must be moved from cross bond into running bond, this the Probst clamp can do automatically without requiring extra work while picking up the block layer. A hydraulic rotator with a slewing range of 300 degrees between boom and installation clamp facilitates quick and precise alignment of the clamp from the driver’s seat. No additional helper is needed for this.
What had impressed TS-Bau, and what apparently strongly influenced its decision in favor of the VM 204, is the patented automatic release device ADV with which installation clamp HVZ-uni in the paver laying machines from Probst are equipped. This is the reason why this particular device in this particular form is exclusively available with the paver installation machines from Probst,
A good construction logistics provided, up to 1.000 m² block pavement can be laid per day with a VM from Probst. This performance factor was also achieved in processing the project “Container Storage area Hamburg Port.”
For the pavement to be laid there, relatively wide joints of 8mm width had been specified. In interaction with the ADV technology and the other functions of the installation clamp, this specification could be met with the required high precision and without much extra time.
Around six million blocks with a total weight of 50,000 tons were needed for paving this container storage area covering 170,000 m². Every block layer (1.1 m²) weighs approximately 300 kg, because of the great thickness of the blocks.
The extraordinary off-the-road mobility and the easy maneuverability in the most cramped spots achieved with the dual articulated steering of the Probst installation machine again and again impresses the operators. The lifting height of the boom of 1,6 m makes it possible that two block packs stacked atop each other can be removed at a time as well. The operators of TS-Bau felt immediately at ease with the previously unknown installation machine VM 204, without requiring much training. That shows clearly how easy and uncomplicated the machine can be handled and how simple it is to adjust the installation clamp to the block formation to be installed.
By now, TS-Bau Torsten Stengelmann has two VM 204 installation machines from Probst. The company completed the paving job – using both of these machines – in three sections on schedule and with a high quality result. Accordingly, the investment into these machines has paid off already now.
