Using Vegetables to Fortify Building Materials
Marie Donlon | July 23, 2018Considering the impact construction projects have on the environment — with the concrete industry responsible for the production of a vast amount of carbon dioxide (CO2) — researchers from Lancaster University in the U.K. are exploring how adding root vegetable fibers to concrete might improve the strength of the material as well as making it more eco-friendly.
In an effort to do so, the research team, led by Professor Mohamid Saafi from Lancaster University, will explore how to incorporate nanoplatelets taken from the fibers of root vegetables such as sugar beets and carrots into concrete. So far, early tests have demonstrated the enhancement of concrete’s mechanical properties with the addition of the sugar beet and carrot nanoplatelets.
According to Prof. Saafi, the cement nanocomposites "are made by combining ordinary Portland cement with nanoplatelets extracted from waste root vegetables taken from the food industry."
"The composites are not only superior to current cement products in terms of mechanical and microstructure properties but also use smaller amounts of cement," Prof. Saafi said in a statement. "This significantly reduces both the energy consumption and CO2 emissions associated with cement manufacturing."
By adding nanoplatelets to the mixture of water, aggregate and Portland cement, thereby increasing the amount of calcium silicate hydrate (which is responsible for increasing the strength of concrete), the team found that the mixture increased the strength of the concrete so much so that they needed 40 kg less Portland cement per cubic meter of concrete than with standard mixes, which means a corresponding reduction in the production of CO2.
The addition of nanoplatelets to the mixture also resulted in a material that performed better than other additives such as carbon nanotubes or graphene. Likewise, the material was also less expensive to produce and longer-lasting.
The last time I was involved with a large concrete pour, we were using nylon or polyester fibers added to the mixer truck at site with such things as silicone fume and fly ash also in the mix. The fibers worked to almost replace reinforcing in a large slab; however, the finish would show signs of the fibers in that if painted the slab took on a "hairy" appearance. I am wondering if the beet fibers are less visible and what kind of compression strength is attained. Also, are the fibers actually longer lasting to the extent that the concrete would not disintegrate under the stress of brine solution such as in northern climate parking garages and highways?