ECOTRM: Eco-friendly concrete for climate-friendly facades

Steel-reinforced concrete consists of a sand and gravel mixture, cement and steel reinforcement. As part of the ECOTRM project, the RWTH Aachen Institute of Textile Technology (ITA) is now carrying out research on an alternative to steel-reinforced concrete – a concrete which consists of a climate-friendly binding agent as well as basalt fibres. The project aims to develop a building material free from cement, the costs and material characteristics of which are similar to those of steel-reinforced concrete. After all, during its manufacture alone, cement causes more CO2 emissions worldwide than all air traffic combined.

The eco-friendly concrete developed as part of the ECOTRM (Eco Friendly Textile Reinforced Material and System for Building and Construction) project consists of an alkaline-activated climate-friendly binding agent made of plaster, fly ash and slag. The latter two components are waste products of the blast furnace process typically used in steel manufacturing. Instead of steel, the researchers use basalt fibre for reinforcement in this project. Basalt is a volcanic rock and – due to the natural eruption – can be considered a renewable raw material. At the same time, it well exceeds the material characteristics of steel in terms of strength, but is less than half the weight.

Engine for progress:

  • CO2 emissions reduced by 80% compared to steel-reinforced concrete
  • Improved environmental balance sheet due to the use of waste products and renewable raw materials
  • Half the price of fibreglass concrete
  • Very good chemical resistance

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Photo: ITA

The demonstrator unit from the previous project: a roof element made of textile-reinforced concrete with only 20 mm wall thickness.

The newly developed eco-friendly concrete is classified as a textile-reinforced concrete composite material. These are types of concrete which are up to 75 per cent thinner than steel-reinforced concrete yet can cope with equal or higher loads. Textile-reinforced concrete can be used to build thinner walls, more delicate structures and in a more resource-conserving way than with steel-reinforced concrete. Apart from a cement, gravel and sand mixture, textile-reinforced concrete usually consists of expensive glass or carbon fibres. In their project, the researchers from ECOTRM rely on economical basalt fibre instead. This makes eco-friendly concrete only half the price of textile-reinforced concrete with glass fibres. At the same time, the quality remains the same. Compared to steel-reinforced concrete, CO2 emissions are reduced by 80%.

Application in building façades and waste water pipes

The eco-friendly concrete can be used anywhere low wall thickness is advantageous, for example in building façades. The basalt fibres make this building material especially acid-resistant. Thus, there is a potential application in using it as a material for waste water pipes, since the pH value of the waste water drops more and more due to continually decreasing waste water quantities. An application as asphalt concrete is also conceivable, especially in areas where a lot of road salt is used.

The ITA is a globally-recognised expert in the area of textile-reinforced concrete and is also carrying out research on the further development of climate-friendly types of concrete and cement in other projects. In tandem with its project partners, the ITA is planning to sell licenses for the eco-friendly concrete and to bring the product to market maturity.


Photo: Till Quadflieg

"Buildings are the spaces in which we live. In the future, textile-reinforced concrete made of basalt fibres will meet our need for sustainability, durability and aesthetics."

Dr.-Ing. Till Quadflieg, Head of Fibre Composite Materials

Partners and sponsors

  • Institut für Textiltechnik (ITA) der RWTH Aachen
  • Korea Institute of Civil Engineering and Building Technology (KICT)
  • Albani Group GmbH and Co. KG
  • CareCon Co Ltd.
  • Bundesministerium für Wirtschaft und Energie (BMWi)