Concrete is a mixture of cement, aggregates (e.g. gravel, etc.) and water. To increase its strength, steel fibers are sometimes added. Now, scientists say the new fiber-reinforced concrete will soon become a lighter, greener alternative.
The experimental building material was developed by Amir Hajiesmaeili, a Doctoral Student working in the Structural Maintenance and Safety Laboratory of the Swiss Federal Institute of Technology. Instead of ordinary steel fibers, this material contains a fiber made of very hard polyethylene. Not only do they provide the same amount of structural support as steel fibers, but they also adhere well to the cement. As a result, only about half of the cement is needed.
This is noteworthy because traditional Portland cement production is a major source of greenhouse gas emissions. In fact, Hajiesmaemeili claims that the manufacture of his ultra-high-performance fiber-reinforced concrete (UHPFRC) produces 60 to 70 percent less CO2 emissions than regular steel fiber concrete. In addition, the weight of the material has also been reported to have been reduced by 10%.
The new UHPFRC material will be used to reinforce bridges next year, which will be the first practical application of this material. “With this material, we can add value by ensuring long-term use of the structure,” said Eugen Br?hwiler, head of the laboratory. The solution is more financially and environmentally sound than the renovation and reconstruction of existing buildings, such as bridges and historic sites. “