Recycling wind turbine blades into concrete

Ground wind turbine blades, which are typically hard to recycle, were transformed into fine glass needles and added to concrete in a study published in the journal Materials in July 2024. Researchers from Northeast Forestry University in Harbin found that this process could significantly improve the material's properties.

Processing the blades for concrete

The blades, made of glass fiber and resin, were processed through a three-step method involving cutting, grinding, and sieving to extract usable fibers. These fibers were then mixed into concrete at concentrations of 1%, 1.5%, and 2% by volume.

Flexural strength improvements

Test results from concrete samples, after 28 days of curing, showed a flexural strength increase ranging from 5.37 to 18.5% compared to standard concrete. This improvement was attributed to the fibers' ability to stitch microcracks formed under bending stress.

Compressive strength changes

While the flexural strength increased, the compressive strength of the concrete showed mixed results, with gains ranging from 6.04 to 18.12%. However, the maximum compressive strength recorded was 19.25 megapascals, and it decreased as the fiber content in the mixture increased.