New Developments in Formwork and building material machinery

Rugged formwork for ceilings that is “dead easy” to mount from below, a device that allows the user to establish the required pressure for concrete pumps in no time and a recycler that for the first time makes it possible to re-incorporate reclaimed asphalt 100%. These are just some of the innovations the producers of building materials machinery and devices are using prove their innovative power.

The device looks pretty inconspicuous. It consists of a barely 80 cm high cone-shaped metal structure, which is roughly 20 cm wide at the top end with a roughly twice as high transparent plastic tube wrapped around it. But as compact as the device developed by engineers and technicians of the concrete pump manufacturer Putzmeister may be, its benefit is huge. It is the first device to achieve the pressure required to swiftly pump different concrete formulas through pipes. So far this had required extensive pump trials especially for large-scale building projects – and these cost money. “Amounts can be as high as several tens of thousands of Euros,” says Dr.-Ing. Knut Kasten, who is in charge of the application technology division in the development department of Putzmeister. But this is now a thing of the past.

Putzmeister has developed a so-called rheometer – i.e. a measuring instrument designed to detect the flow and deformation behaviour of mass – in this case of concrete and/or slurry. The result is a device that can be operated by virtually anyone both at the lab and construction site after brief training. Summing up Kasten, who invented the device and wrote his doctorate thesis about this new process at the Technical University of Dresden, said: “With our Sliding Pipe Rheometer the costs incurred so far can be cut noticeably.” However, the rheometer whose backbone is formed by a sophisticated computer software, is not for sale. At least for the time being the analysis is only offered as a service.

The engineers of the Swiss construction and building material machinery manufacturer Ammann focused not so much on mass flow behaviour but more on the reuse of building materials and road asphalt, in particular. They developed a device, which – in an ideal case - recycles 100% of reclaimed asphalt (RA) and reincorporates it into new surfaces. “The limit”, explains Sales Manager Ulrich Winkelmann, “currently stands at 65 % to 70 %”. When incorporating higher percentages most of the plants currently available on the market would substantially exceed the waste gas limits in force in industrialised nations. We can achieve some 75 % to 85 % on average, says Winkelmann, with an hourly output of up to 280 tons.

Unlike the conventional systems where the material and the heat are introduced into the recycling drum from the same side, the “100 % RA Mixing Plant” from Ammann operates on the counter-flow principle. Heat is introduced into the drum from one side while the material is introduced from the other. The drying and further heating processes are therefore far more energy-efficient according to Winkelmann. The asphalt can be heated to 180 degrees – a temperature that is impossible to achieve with conventional systems because of the exceeded limit values. “Realistically,” Winkelmann says “in excess of 130 % is hardly feasible.”

Formwork for ceilings that can easily be erected by just one person from below was launched by the Southern German Formwork and Scaffolding Manufacturer PERI and awarded with the EuroTestPrize 2010 by the Berufsgenossenschaft Bau (BG Bau – Employers’ Liability Insurance Association). It honours outstanding achievements in the area of occupational health and safety. The principal component of the GRIDFLEX formwork is a 2 m long and 1 m wide aluminium grid slab that weighs in as little as 20 kg. It is hooked in at one end at two ceiling supports, swivelled upwards at the other with the help of an extensible bar and placed on two other wall holders. The plywood sheets can then simply be laid from above.

In addition to the powder-coated white main component there is a red element for transverse and longitudinal compensation as Dipl.-Ing. (FH) Alexandra Pfister, Product Manager at PERI, explained. These telescopic filler elements can also be hooked into the basic element from below. This also applies to the required fall-arresting devices which are also pre-assembled on the ground and then swivelled upwards. Pfister explains: “With our GRIDFLEX just three elements are enough for fast and safe shuttering of any geometry from below.”