The city of Ålesund (pronounced Ole-sund), with a population of 43,000, is located on several islands connected by bridges and undersea tunnels along the western coast of Norway. After the city burned down in 1904, it was rebuilt with concrete buildings - both residential and commercial - to avoid such a tragedy from happening again. The houses were built in a beautiful Art Nouveau style (Jugend style). Ålesund is a town that hascome to love concrete.
Fishing and farming have been the primary occupation in the Ålesund area, but today ship building and the oil industry also have strong presences. The entire country of Norway has become wealthier as a result of oil wells along costal areas and in the North Sea. The economic crisis that has gripped most of the world doesn't exist here and the construction industry thrives.
Ove Nordstrand, owner, Dekorbetong Ltd., Nordstranda, Norway, says concrete has been part of his life for more than 40 years in the Ålesund area - both before and after his technical education. He has experience with concrete formwork, carpentry, and construction management. In 1984, he started a ready-mix concrete producer business to serve the bridge projects and undersea tunnels that were being built in the area. It was during this time he experimented with ways to apply decorative treatments with concrete, without knowing that companies in the U.S. already had developed tools for stamping patterns.
In 1992 he attended a concrete exposition in Copenhagen and discovered that he could buy stamps and materials designed for decorative work. He started Dekorbetong Ltd. in 1995 after he closed the ready-mix plant, deciding to focus on decorative concrete. He thinks he has one of the first companies in Norway involved with decorative concrete work. He says although his company isn't large - it employs three full-time crew members and hires additional help for larger projects - they have completed a lot of work.
Decorative concrete is relatively new to Norway. Nordstrand's company travels to towns throughout his area to install work but he has begun to train and franchise other concrete contractors in towns large enough to support the decorative market. Today his company installs colored concrete, stamped concrete, diamond polished concrete floors, concrete countertops, acid staining - even concrete window sills. But the company's most interesting product, the one which captured the attention of the Concrete Construction editorial staff, is what he refers to as "vertical concrete construction by free hand."
Vertical concrete by free hand
During the years he owned the readymix company, Nordstrand experimented with concrete mixes, hoping to develop a mix that could be used for vertical applications without slumping. He settled on a mix with ? inch top-sized aggregate including well-graded stone and sand sizes in order to minimize void spaces between them, following a gradation curve. The mix also included a more than usual amount of portland cement. By the time he started his company, he already had a concrete mix for doing vertical work, so his biggest challenge was to develop the craft skills needed to offer clients something very unique.
After reading this you might be asking yourself the question, "Why bother?" The simple answer is that you achieve shapes at reasonable cost you can't create with formed concrete. Three-dimensional rounded surfaces are easy to construct when they are "free handed," when you have the right mix design and skill to shape them properly.
The concrete garden
With great views of the ocean sound and the mountains, homeowners Jorunn and Tore Aakre from Ellingsoy in Ålesund wanted an outside veranda to take advantage of the scenery - adding an outside living area. Nordstrand met with Jorunn to work out the concept, then Nordstrand provided the final design and drawings. The project included an addition to their hillside home, a second-story level concrete deck, retaining walls, a fountain and spa, planters, seating areas, a textured patio deck, and a curving stairway leading to the upper floor of their house. Every concrete element would include colored, textured surfaces.
Nordstrand says it took four workers four days to complete their portion of the project. Other contractors constructed the second level deck and the concrete block retaining walls, which he provided the vertical decorative work. His team completed all the vertical elements first. Readymix that wasn't too stiff was delivered and dumped on the ground. Workers shoveled it into position for the planter curbs and batter-retaining walls. Then they created the shapes with hand floats, applied a handshake color, stamped impressions, and finished the work with a sealer application. Some of the battered walls were as high as 4 feet.
Their greatest challenge was the curving steps leading to the second-story deck. Nordstrand says they filled the void under the steps with polystyrene foam to support the steps during placement and until it developed its design strength-removal afterward created a small storage room. They placed ? inch rebar (10 mm) on an 8-inch grid (20 cm) in the walls and in the structural layer of concrete under the steps.
Two separate placements created the steps, both performed on the same day. When the first load of ready mix concrete arrived, workers placed it in the wall areas on either side of the steps and on top of the polystyrene in the structural layer under the step risers. They used shovels and hand floats to accomplish this. Then they applied dry-shake color hardener and stamped textures on the surfaces. A second load of ready-mix was used to construct the actual steps, starting with the top one and then the second, down to the last. Each curving step was shaped with hand floats and troweled, colored with dry-shake color hardener, and stamped with a texture.
When you think of Norway and places like Ålesund, visions of mountains, fjords, glaciers, and dramatic views come to mind. Decorative concrete isn't what you expect to see, especially in an out-of-the-way place like Ålesund. But Nordstrand hopes to change all that by teaching his skills to contractors from other towns, completing Norway's beautiful surroundings.
It isn't often that CC sees an all new decorative technique-we went all the way to Norway to see this one.
On this project we have used ready-mixed concrete, poured directly on the site from concrete trucks. Then we molded and shaped the fresh concrete (handmade) to become vertical stairs, edges and water pool as shown in the pictures. The entire construction is shaped by free hand without any shuttering. Finally, we cast the concrete floor. We treated the fresh concrete surface partly with Desert Tan color hardener and Classic release before we stamped with seamless pattern. After curing and washing we applied concrete sealer to the surface. Four people spent four days to carry out the project.
The most unique element of this project is the method and the technique we use for molding and hand shaping fresh concrete to become vertical constructions such as stairs, walls and edges, etc. In this case, the most unique part perhaps is the stair connecting the upper level porch with the basic level in the garden. We just dumped the ready-mixed concrete on site, and than immediately we did the casting and handmade shaping. First we formed the side walls of the stair before we finished the steps. The reinforcement we had mounted in advance, and the concrete also contain some plastic fiber.
Our company Dekorbetong Ltd. are located in Ålesund, Norway, and we make Decorative Concrete in this market. We have developed our own method that makes it possible to mold and shape the fresh concrete to become creative and vertical concrete constructions by free-hand without use of formwork. We also use known Decorative Concrete technology as stamped concrete for the finish of the surface.