Concrete

Norwegian concrete research is world class

By Denise Wergeland
January 29, 2007

The oil adventure started in 1969 for Norway and boosted Norwegian concrete research. The knowledge from the construction of oil platforms took concrete from being an ordinary industrial product to an advanced high-tech material. Now, the concrete industry sees innovative opportunities once more.

Photo of Realfagbygget, one of NTNU's builidingsOver the next eight years, researchers at SINTEF and NTNU will make it possible to create functional concrete buildings with longer life and smarter constructions than anything on the market – in addition, they are more environmentally friendly. The secret lies in the researchers’ knowledge about the composition of the material itself and how it affects the final product.

COIN is a research-based innovation centre that will help industry build concrete buildings of the future.

Thanks to the vigilance of the researchers in Trondheim even before the offshore phase, industry has invaluable knowledge about the potential of concrete as a material. The offshore success spurred the concrete industry to try new solutions which led to breakthroughs and more research.

Pioneers of strong lightweight concrete
The Norwegian Public Roads Administration was inspired to build strong floating bridges in lightweight concrete in exposed areas on the west coast and in northern Norway. Nobody, either in Norway or abroad had ever dared to do anything like this before, probably because making strong lightweight concrete is a very advanced process.

Lightweight concrete is the most suitable material for floating structures such as oil platforms, floating bridges, and long-span bridges. However, the lightweight concrete must be strong enough to endure heavy strain, particularly from natural forces. In this connection, the decisive factor is the composition of the material.

Illustrasjonsbilde/FOTOEarly phase important
Even though concrete is currently the most common building material in Norway, its potential is still not fully utilized. Researchers are looking for new ways of constructing attractive concrete buildings for the future. This means first studying the material. One of the COIN centre’s tasks is to develop stronger and more environmentally friendly concrete that will last longer than concrete does today. In addition, researchers will bring in interdisciplinary expertise: chemists to look at the raw materials in the cement and how the substances react together, geologists to assess sand and gravel deposits, as well as contractors, civil engineers, structural engineers and architects.

Durable reinforcement
Steel bars are normally used to reinforce concrete at present. However such steel reinforcements of this type may become corroded in exposed environments such as a bridge in seawater and such corrosion will significantly reduce the operational life of the concrete. If the reinforcement work is not carried out exactly, corrosion on this type of reinforcement can occur sooner than expected. One way of avoiding the problem is to use non-metallic reinforcement, such as glass-fibre or carbon-fibre. There is a market demand for tailor-made and pre-fabricated solutions such as fibre reinforcement mixed directly into fresh concrete that will save both time and money. However, mixing in the desired amount of fibres is a complicated process. This is one of the areas of research that COIN will investigate to find solutions that are less expensive in use.

Intelligent warning systems
COIN will also conduct research on intelligent systems that can monitor and provide alerts if steel reinforcements start to corrode. It is possible to cast sensors into the concrete that will signal when there is a risk of reinforcement corrosion. These sensors will trigger a switch that releases enough current to counteract corrosion.

Photo of Realfagbygget, one of NTNU's builidingsEnvironmental considerations more important
The building industry has to meet strict requirements regarding environmental considerations. Cement is a material that in principle causes environmental damage in the production process, mainly because the raw material, limestone, produces large amounts of CO2 when being burnt into cement.

“One way of reducing the amount of CO2 could be replacing some of the limestone by other materials,” says Tor Arne Hammer, the Research Director at COIN.

”We could use alternative materials such as stone that is already crushed or various types of filter dust. In that way, we can also save energy when pulverizing,” Hammer explains.

Using recycled material
COIN is working to develop new types of cement that consume less energy in production. In addition to the CO2 emissions that contribute to the greenhouse effect, producers must pay high taxes that increase production costs.

Concrete consists of approx. 70% sand and gravel taken from riverbeds and moraine deposits. Extracting this material can cause environmental conflicts as a result of severe disfiguring scars in the landscape. Due to the limited supply of sand and gravel, the authorities in some parts of Central Europe have instructed concrete producers to use a certain percentage of recycled material in production.

Illustrasjonsbilde/FOTOMore concrete and less workers
COIN will work to develop concrete with the best possible production qualities. The purpose is to simplify the production process such as producing self-compressed concrete - a liquid concrete that compresses itself. This process means that there is no need for workers to compress the concrete with vibrators, an operation that often led to repetitive strain injuries from working with the vibrators. One type of liquid concrete is already in use, but is relatively expensive at the moment. Research is being conducted to develop less expensive solutions.

Sandwich elements
COIN will also research untraditional construction methods. Composite construction is one of these where a structure is composed of at least two different materials. For instance, sandwich elements that consist of some sort of protective skin of super-strong concrete, or steel surrounding lightweight concrete. Here, the outer skin functions both as formwork and reinforcement. This could also be carbon material glued to ordinary concrete as reinforcement. In both cases, the fibre reinforcement strengthens the actual structure.

Multi-functional concrete buildings
Concrete can be used as a heat or cold reservoir to maintain a more constant temperature and reduce the energy consumption needed for heating or cooling a building. By being energy-efficient this solution also brings positive financial effects. In addition, the self-cleaning surfaces can contribute to cleaner air due to the reduced amounts of undesirable organic substances in the air.

Photo of concrete as an aesthetic material Concrete is beautiful
Concrete can be fun and colourful as well – the sky is the limit. For example, it is possible to mix coloured glass and beautiful stones into the concrete that will give an attractive finish when the surface is polished. It is also possible to make ornaments in the surface or coloured concrete. There is increasing interest in concrete among architectural students. Concrete is gaining acceptance as an aesthetic material.


 

FACTS ABOUT COIN:

Name of Centre:
COIN Concrete Innovation Centre

Vision:
The main objective of the Centre is to become the leading European institution in concrete innovation. Advanced materials, efficient construction techniques and new design concepts will be developed in combination with more environmentally friendly material production.

Host institution:
SINTEF Building & Infrastructure

Research Centre Director:
Tor Arne Hammer, SINTEF Building & Infrastructure

Number of staff/students at the Centre/in the research group:
No permanent staff, but at any time approx. 6 researchers and 6 PhD students will be working on projects related to the Centre.

Partners:
NTNU, Norcem, Unicon, maxit, Rescon Mapei, Borregaard, Elkem, Aker Kværner, Veidekke, and the Norwegian Directorate of Public Roads.

Total budget:
NOK 210 million

Duration of project:
2007 – 2014

Postal address:
SINTEF Byggforsk, Betong
NO-7465 Trondheim, Norway

Offices and laboratories:
SINTEF Byggforsk (Building & Infrastructure), Betong,
Richard Birkelands vei 3
Trondheim, Norway

Contact:
Email :tor.hammer@sintef.no

Centre for Research-based Innovation (CRI):
The establishment of the Centres for Research-based Innovation emphasizes Norway’s long-term prioritizing of R&D for the business sector. In 2006, a total of 14 Centres were established.

The main objective for the Centres for Research-based Innovation is to enhance the capability of the business sector to innovate by focusing on long-term research based on forging close alliances between research-intensive enterprises and prominent research groups. (In the long run this basic research will also benefit small and middle-sized enterprises that lack their own research departments.) The total budget for the 14 CRIs will amount to NOK 2 billion over the next eight years. The contribution from the Research Council of Norway is NOK 1 billion. The host institution and its partners contribute NOK 500 million each.