Stairs around a hearth (center of the square (piazza)) creates a vertical path, the road, leading to niches creating windows and individual rooms.
In the dense September fog the Full Scale Studio went on a field trip to watch building material come to life. We became aquainted with the processes behind the preparation of building materials such as Limestone, Stainless Steel, Brick and Sawn Timber. Follow our tour in Bergslagen, Sweden below and learn more about bringing life into these building materials.
The brickfactory in Haga is today the only excisting brickfactory in Sweden and with an increase in demand for brickwork, the future seems to be bright.
The clay used for the production comes from farmland in the neighbourhood why the production can be classified as ecological. The principle is simple; the topsoil is moved to the side while the clay is being digged up. When this is done the topsoil is put back and the farmland is redo to be reused.
Brickbuildings from the national romatic era around the 1920’s were made by hand which gives every stone a unique appearance. Today a similar method can be used but with a machine but it is still very expensive. At Haga, a method called “stringpressed”, is used.
THIS IS HOW IT WORKS
- A tractor fetches the clay from a local farmland
- The clay is pilled up near the factory and regularly transported to a vessel on the inside
- From the vessel, the clay is transported to a tumbler where sawdust, sand and, if necessary, water is added (depends on the moisture content in the soil)
- The mixed clay is then transported to a big vault where it is stored and matures over time.
- The matured clay is picked up by a band with scoops which bring it to a compressor where it is processed and pressed into a compact dough which is pressed out of a rectangular shaped nozzle. The result is a loaf of clay.
- The clay loaf is thereafter cut with a thin thread which leaves several clay blocks with brick dimensions.
- The clay blocks are then fetched by a trolley and left in a drying cabinet where it is stored for three days.
- When the blocks are dry, a trolley brings the clay to the oven where it stays for five days to become brick
- Finally the brick is being wrapped in plastic and put in a storage
STRUCTURE AND COLOR
The stringpressed brick can be made with different textures and nuances. By covering the brick in sawdust that incinerates in the oven a texture is achieved. As the texture comes from an organic process every piece of brick gets its own character. Different types of sawdust generate different types of textures.
The color range could be considered as wide. By regulating the amount of oxygen during the process in the oven as well as setting the temperature, the color is affected. The lower the temperature the brighter the brick. Yet it is not possible to achieve brick with a nuance similar to terracotta since the temperature required is too low to make it frost resistant.
Outokumpu Stainless Steel
Outokumpu is a global leader in stainless steel with cold-rolling capacity of 2.6 million tonnes. They create advanced materials that are efficient, long lasting and recyclable – helping to build a world that lasts forever.
Stainless steel is an ideal material to create lasting solutions in demanding applications from cutlery to bridges, energy to medical equipment. Stainless steel as a material is 100% recyclable, corrosion-resistant, maintenance-free, durable and hygienic.
Outokumpu's operations in Sweden include integrated stainless steel mill in Avesta and cold rolling mills in Kloster and Nyby. All of the Swedish mills focus on high performance stainless grades, and they became part of Outokumpu after Avesta Sheffield acquisition in 2001. Together, they form the Avesta business line in the Coil EMEA business area.
Outokumpu's integrated stainless steel mill in Avesta includes melt shop, hot rolling mill and cold rolling mill. Avesta produces thick, two-metre wide coil and plate, with particular emphasis on special grades, such as duplex grades. The site also houses an R&D centre. Avesta, together with Nyby and Kloster mills, is part of the Avesta business line in the Coil EMEA business area.
The Avesta site has a long history of producing steel, especially duplex grades: Avesta invented and produced first commercial duplex stainless steel in 1924.
Outokumpu has been instrumental in developing the stainless steel industry into what it is today. Indeed the history is as old as that of stainless steel itself, dating back a century to sites in Germany and the UK where stainless steel was invented in the beginning of the 1900s and in Sweden, where duplex was invented.
The production facilities now cover all continents and are located in China, Finland, Germany, Mexico, Sweden, the UK and USA.
The mills in Sweden produce high-performance stainless steel, from high-alloyed austenitic to various duplex grades. Outokumpu even owns the largest known chromite reserves in Europe and thus has unique competitive advantage in its access to raw material that makes steel stainless: chromium.
Outokumpu's stainless steel production is based on recycling, with the main raw material being recycled steel. Radio-actvitiy is checked before the steel can be used in production. If the steel is found to contain radioactive qualities it is returned to the company who brought up.
2. Scrap Pre-heating 300 degrees Celsius:
This process melts any ice or snow that might be on the steel before it goes into the electric Arc Furnace, this prevents any explosions occurring when the steel is put in the furnace.
3. The Arc furnace at 1650 degrees Celsius for 1 hour:
Melting takes place in an electric arc furnace, which is charged with recycled steel and other raw materials – nickel, molybdenum oxide and ferrochrome. A major advantage of Outokumpu's integrated production process is that the ferrochrome produced in-house can be fed directly into the furnace in a molten form, saving considerable quantities of energy.
In this part of the melting process, they add oxygen to reduce the coal component, the steel is therefore refined to determine the composition of the it according to the customers requirements.
5. Adding and adjusting:
The steel is rinsed with sulphur and transported to the ladle furnace. This is where they ensure the correct composition of the steel and make sure it has the correct temperature for casting. Argon gas is allowed to bubble through the steam to remove any informalities within the steel, i.e.; leftover debris.
The steel is cast between 35 to 45 minutes. Steel is cast at a metre per minute which equals a flow of steel of circa 2 tonnes per minute. After the cast is complete, a cutting machine cuts the slabs into approximately 14 meters long (and weighing 20-26 tons). After the casting, some types of steel are sent to be polished so there are no surface defects within the material. The polishing happens at 800 degrees Celsius.
7. Hot grinding:
Slabs of stainless steel, are transferred to the hot rolling mill. The steel has a thickness of 140-200mm at this stage and is reduced to somewhere 2.5mm and 12.7mm with a length up to 1km. The temperature is raised to 1250 degrees celsius within the mill. The steel is transported through the mill 3 to 9 times depending on the thickness needed at 1010 degrees calcium. When the steel is ground, it gets rolled into a band roll, that is then weighed, marked and sent to cool off. First in the air and then in water. The steel is either then sent to the customer or to the cold grinder.
8. Cold grinding:
The steel gets to cool off under controlled circumstances for the steel to be the correct mechanical requirements. The steel is then sandblasted to clean the surface of the steel. Two thirds of the material is then sold as heated and sandblasted hot ground steal and the other third that is left goes to be cold grinder again. In the cold grinding process the steel is ground down to 1.5mm at the thinnest. The cold grinding gives the steel a nice finish. The steel sheet is finished off, it is cut into certain dimensions depending on the customer.
The limestone is primarily sourced from the nearby limestone quarry at Forsby, which lies 40km away from the Nordkalk factory near Köping. While a cable-car system was used to transport it ever since the 1940s it was decommissioned in 1997 in favour of trucks. Long-distance deliveries of limestone are mostly done by ship via a canal that connects the factory to the Baltic sea, with imports arriving from Gotland and France.
The raw limestone is crushed, ground and sifted in varying degrees of granularity before being moved to an intermediate storage.
In order to transform the ground limestone (calcite) into quicklime (calcium oxide) it is heated to a maximum of 1400 °C, with a minimum of 800°C being required for the reaction to take place. The cylindrical steel oven is coated with an internal brick layer, which eventually breaks down and is cleared by firing 2000 shells into it on a regular basis. The oven is fuelled with coal, while they are currently considering how to utilize a different energy source such as bio-fuel or wood pellets.
Transforming quicklime into slaked like (calcium hydroxide) only requires the adding of water. Depicted above, you can see the exhaust moisture emanating from the cooling tower.
Limestone has historically been used as a structural building block, yet today it is primarily used only as tilework in its cut yet unprocessed form.
Ground limestone powder itself is used as a filler in the building industry, white coloration in plaster, concrete and road markings, and as a food supplement in chicken feed.
The reactive qualities of quicklime is used in the steel manufacturing process to remove impurities in iron ore, neutralize the pH level of lakes and agricultural soil, and in the petroleum and paper industry.
While quicklime is provided directly to the cement industry, it is solely for the purpose of mixing it with water to produce slaked lime, which is used as a binding agent within a concrete mixture, both for structural concrete as well as stucco/plaster/mortar.
To make concrete lime is a primary ingredient. Concrete consists of a filler agent and a binding agent, where the binder glues the filler together to form concrete. There are many different types of concrete, in which the filler consists mostly of gravel or other infill materials in different sizes, and the binder is a mixture of cement and water. The cement consists of a limestone and clay mixture. These materials are crushed and then heated to 1500 degrees to form a powder called clinker .The heating process is done in a big rotating furnace, with cement being the final product. Later when making concrete water reacts with the cement and binds the filler to a stable form to create concrete. The process of making cement is done at Slite on Gotland where there is a big factory and a quarry. The process of heating up the limestone uses coal as fuel which is consumes large quantities of energy and generates large amounts of CO² emissions.