Since 2008, the Brazilian Marna Pré-fabricados Group has been consistently concentrating on precast element architecture. The stair production line has now been extensively modernized by adding a Variostep 170-17 stair mold from Vollert’s special product range.
Precast concrete stairs have become a key feature of the Brazilian construction industry. In modern residential and industrial construction, industrial prefabrication and very short erection and assembly times result in major cost and quality benefits. Marna Pré-fabricados, the construction specialist, has also identified this advantage. Since 2008, the company has been pioneering the manufacture of state-of-the-art bridge beam structures in Brazil at its production facility in Pinhais, near Curitiba. Its range has since been expanded to also include precast elements such as columns, girders, and hollow-core floor slabs. “Today, we contribute to shaping the face of Brazil in modern commercial construction, including in factory buildings, warehouses, and multi-story car parks,” says Marna’s Managing Director, Guilherme Philippi. “We expanded our production capacity again in 2017 to be able to serve additional major projects. Also, an extremely variable stair mold allows us to produce an exceedingly wide range of concrete stair designs and dimensions for a wide variety of construction projects.”
Engineered in Germany, made in Brazil
The Variostep stair mold is part of Vollert’s special shuttering portfolio. The special feature of this stair mold is that it was manufactured to the high German quality standards in Brazil. “You could describe it like this: engineered in Germany, made 100% in Brazil. As the engineering partner, we provided the entire construction expertise and permanently supervised the welding and assembly work. In so doing, we used only materials and steel components that were manufactured exclusively in Brazil,” explains Wesley Gomes, CEO of Vollert do Brasil.
The structural design of the stair mold provides utmost flexibility. Both clockwise and counter-clockwise rotating stairs with up to 17 steps are produced in an upright position. A modular side wall enables stair widths of 950 to 1,700 mm to be produced. The tread varies infinitely from 220 to 320 mm and the pitch from 150 to 200 mm, whilst the step hypotenuse is defined by means of a setting gauge. “We can produce very versatile stair configurations, and the changeover time, for example for adjusting the stair width to the next construction project, is minimal,” says Guilherme Philippi. The step thickness can be varied between 100 and 200 mm. A further advantage is that the stairs are produced in the Variostep stair mold on the stringer side, which ensures impeccable fair-faced concrete quality on three sides. Steps are manufactured in a right-angled, and thus sharp-edged, design, which is another distinct quality feature of precast stairs. This is important in particular when carpet floorings or ceramic tiles are applied at a later stage.
Attaching a landing for stair access and egress is particularly simple thanks to the horizontally movable and height-adjustable steel rear wall and is possible at any step. Movement of the side wall to absorb the concreting pressure is ensured mechanically by gear wheels and tensioning bolts. Opening and closing is thus particularly easy and user-friendly.
Developing visions to help shape Brazil’s future
Marna Pré-fabricados is already using the new precast stairs in many construction projects. “The new multifunctional stair mold enables us to produce top-class fair-faced concrete surfaces – and our customers confirm that. This quality standard sets us apart from our competitors,” says Guilherme Philippi. “At the same time, we can manufacture a wide variety of concrete stairs.” The company is already working on further major proj-ects – and on new ideas, too – in order to help shape Brazil’s future with modern architecture that transcends conventional standards.