Photo: Thor Nielsen

Set in concrete



  • Master’s degree in Inorganic Chemistry, NTH, 1978
  • PhD in Inorganic Chemistry, NTH, 1983
  • Post Doc at Rensselaer Polytechnic Institute, Troy, New York, 1983-1984
  • Worked with cement and concrete at SINTEF since 1985, now Chief Scientist
  • Adjunct Professor at the Department of Materials Science and Engineering, NTNU, since 2000
  • Visiting Professor at China Building Materials Academy, Beijing
Concrete research scientist Harald Justnes was recently awarded an honorary professorship at China’s University of Xian, the city that was originally home to the terracotta soldiers. This is in recognition of his environmental commitment to China. He has also taken on the role of a travelling warrior with environmental technology as his weapon.

Justnes’s efforts are providing much needed assistance to the Chinese: 16 of the 20 most polluted cities in the world are in China. The country’s economy is exploding and the construction rate is higher than ever. A full 50 per cent of the world’s cement is produced here – and it creates 26 times as much CO2 as Norway’s total emissions.

Harald Justnes is therefore teaching the Chinese to burn waste instead of coal in the gigantic kilns that produce cement clinkers. This can be a win-win situation. The environment is protected from an ever-increasing mountain of waste in a safe manner, CO2 emissions are reduced drastically and the industry is saving both fuel and raw materials.

The technology can also burn hazardous environmental toxics. The cement kilns reach a temperature of 1450 °C and provide a long residence time for the materials being incinerated. As a result, the kilns are an effective destruction device that can be utilized instead of purpose-built facilities.

“Are we seeing the start of a dawning environmental consciousness also in China?”

Yes, in recent years the Chinese have been most occupied with raising their standard of living and the consumption of goods and services. Increasingly more are starting to realize the flipside of rapid industrial growth is neglecting the environment.

“You want to replace coal with waste as a fuel in the cement kilns. What challenges does this involve?”

This maximizes the volume of waste that can be destroyed without releasing hazardous substances, while at the same time retaining the quality of both the process and the product. The waste can often comprise many different components, such as paint wastes, printer ink and the like which are mixed together in large tanks before incineration. Analysis and assessment of the properties of the end product can be quite complicated.

“What types of waste are the biggest problems in China?”

The Chinese are relatively good at recycling things of value. The big challenge is probably the handling of household waste and sewage sludge. They also have a few old sins that are coming out of the closet, like contaminated soil in industrial areas. Beijing Cement now feeds its cement kilns with soil contaminated with DDT and Lindane (pesticides). The organic components are disposed of under thorough supervision, while the inorganic part of the soil also becomes part of the cement clinker.

“The disposal of waste such as DDT in cement kilns is something groups like Greenpeace has voiced scepticism about. Why is this?”

I think that is probably something you need to ask Greenpeace about. Our experience is that you achieve 99.9999 per cent destruction of substances such as DDT. DDT is a persistent organic pollutant that collects at the top of the food chain because it is liposoluble. It has affected among other things the egg laying patterns of eagles and the reproduction of polar bears, and DDT is now the subject of a world-wide ban. I believe it is better that pollutants are incinerated instead of entering the food chain.

“Increasingly more are starting to realize the flipside of rapid industrial growth without considering the environment.”

SINTEF proposed the project to the Norwegian authorities, and they were willing to pay both us and the Chinese to do the job. This fits well with the present government’s environmental commitment and may function as good will so the Chinese keep an eye out for Norwegian salmon!

“What are your plans when you return home?”

I will work at COIN (the Concrete Innovation Centre), where I am assistant manager. SINTEF Building and Infrastructure has succeeded in housing one of the 14 new Norwegian centres of research-based innovation. When you consider the importance of concrete for modern society, you can probably understand why our application was successful.

The slogan for our application was “attractive concrete” with regard to both aesthetics and the environment. The aim is to partray the potential of concrete and at the same time lift the image of the material to the level it deserves.

By Christina B. Winge