From limestone and carving to concrete and Betemi
Over the years, Finland has welcomed home many an Olympic winner; distance-runners Paavo Nurmi and Lasse Virén as well as our many javelin champions are perhaps most renown. Creativity and excellence also flourish in the Finnish companies of today. Elematic's technology family presents the most modern method for making columns, the Betemi column process. Greek life was dominated by religion and so it is not surprising that the temples of ancient Greece were very impressive and had the biggest and most beautiful columns. The three main types of columns used in Greek temples and other public buildings were Doric, Ionic, and Corinthian. In the 5th century BC, the Parthenon on the Acropolis was built, as was the Temple of Zeus, one of the largest temples in Greece. The building held six columns on each end, with thirteen on the flanks, and, except for the sculpted elements, was built entirely of local shell limestone.
Twist and shape
Today's columns are made of concrete. Bearing and beautiful concrete columns of many sizes, shapes, and surfaces can be created. The Betemi columns are cast with a unique shotcreting method. The core of the column is a tube, around which the reinforcement for the column is assembled. Concrete is slowly sprayed onto the tube, which stands in a vertical position on a carousel and rotates. Simultaneously, a spinning trowel disc shapes and compacts the concrete to form perfectly round columns of consistent quality. Excess concrete is cut off and recycled.
Ten blue cylindrical columns, please!
Molds are no longer needed and the resulting savings are considerable. The process is also highly automated and makes production faster and shortens lead times. In addition, shotcreting makes it easy to produce columns of different sizes - if an architect desires columns with a diameter of 325 mm, no problem! The diameter can vary between 150 mm and 1200 mm. Steplessly! Columns can be cylindrical, conical, or even barrel-shaped. Using molds, the largest stones tend to sink to the bottom, but with shotcreting the stones are distributed evenly in the concrete, and there are also no pores or joint traces. The surface turns out round and even, making possible grinding or polishing faster and less expensive. When a decorative surface is desired, only the outer layer is of more costly material and the internal part is of less expensive grey concrete. The height of the equipment limits the maximum length of columns to between four and five meters, but an extension can easily be added. This way columns can in fact be several storeys high, if needed. The joints are next to invisible.
Concrete aesthetics on the go
The Parma factory in Nummela, some 50 km from Helsinki, produces approximately 2500 Betemi columns a year. Over half of these are made of colored concrete. A majority of the columns go to housing production and are used in facades, as balcony columns or as single-story frame columns. Mr. Hemmo Sumkin, Sales Manager at Parma, says that the Betemi columns are highly refined and make for an excellent export product. Some have been transported as far as Japan. The factory is currently making 111 polished black columns for a building project in Norway, the largest single delivery of the factory up to date. These columns will decorate the 4000 m² large administration center of Sparebanken Hedmark, a Norwegian bank. "We wanted columns for decorative purposes, and so a high amount of aesthetics was required", explains one of the Architects for the building project, Mr. Tore Bergh from Arkitektstudio Hamar AS. "We have received the first deliveries and are very happy with the quality and appearance of the columns", continues Mr. Bergh. "We also realized, that these magnificent columns are actually not expensive, due to the manufacturing process being a highly automated one, and so we will definitely use more Betemi in the future".