Tough Cast technology ensures long lifetime cycles with concrete spreader components

Modern concrete spreaders increase plant productivity in precast concrete plants through precise and fast travel paths and optimized concrete discharge. Simultaneously, they are an essential quality factor for the produced walls and slabs. In order to extend the lifetime cycles of the machine components used, Vollert, the specialist in plant engineering, now relies on new materials. Optimized, process-reliable concreting methods offer significant cost-saving potentials. Precise concrete dosage ensures accurately calculable material usage, CAD CAM-based travel paths ensure significantly faster cycle times. At the same time, new, high-quality components offer prevention of expensive downtimes. An important focus here lies on the most stressed machine components in the concrete discharge process.

Nowadays, in automatic concrete spreaders, the discharge process is very often carried out via screw discharge units, with the screw drives being controlled individually or in groups in automatic mode. Sealing caps ensure clean discharge. A rotating distributor roller prevents the formation of a cone of debris and ensures a good flow of concrete towards the discharge. However, due to the high abrasive stress caused by concrete, the discharge screws as well as the discharge ducts had to be renewed at regular intervals in the past. This caused expensive downtimes in addition to the actual spare parts costs. Thanks to new material mixtures, lifetime cycles are significantly extended.

Longer lifetime in the practical test

„We spent a lot of time thinking about how we could extend the service lifetime of the machine components in concrete spreaders“ explains Markus Schenk, Project Manager Sales at Vollert. „Instead of relying on welded and hardened sheet steel for the discharge screws, as in the past, we came up with cast steel after some pilot tests.“ Fully cast and post-hardened steel is significantly more resistant to wear. In an extensive series of practical tests, an average of 3 times higher lifetime cycles were achieved for the new type of discharge screws with Tough Cast technology.

„Particular is also a special changing device for the discharge screws, which makes it possible to quickly change them as easily as changing a tire on a car,“ emphasizes Schenk. The drive shaft remains in its bearing position when the discharge screw is replaced, which leads to significant time and cost savings. The counterpart of the screw, the discharge duct, has also been further developed. Here, cast iron is used instead of sheet steel. The discharge ducts are inserted individually and can therefore be replaced individually, which makes maintenance much easier. The compact modular design ensures precise concrete discharge. The lower discharge unit can be folded down completely for cleaning purposes. Thanks to this modular design, older concrete spreaders can be converted and equipped with the new technology as part of a retrofitting.

Additional half-flaps lead to early cost savings

Important innovations, apart from the material, are additional half-flaps in the lateral or complete discharge area. Increasingly complex component geometries sometimes result in very narrow concrete contours. „In order to take these requirements into account in the concreting process as well, our Smart Cast concrete spreaders can be optionally equipped with half flaps“ explains Schenk. The concrete can thus be applied very precisely, and partial segments can be completely recessed. „Through such further developments in the component materials as well as in the concreting process, our customers achieve cost savings very quickly. Particularly important to us at Vollert is the practice relate, which we achieve through a permanent exchange with our customers.“