Researchers in Japan and Norway have developed an experimental material that could change the way concrete is produced, using desert sand in combination with plant-based binders for the first time.
Researchers from the Norwegian University of Science and Technology (NTNU) and the University of Tokyo have succeeded in developing an experimental building material that allows the use of desert sand in the composition of concrete, a first in the field.
The project proposes a completely different approach to conventional cement-based concrete by partially replacing it with plant-based binders and natural particles.
The new material, called “botanical sand concrete”, is made by combining fine desert sand with vegetable additives and wood powder, the process being completed under conditions of controlled heat and pressure. The result is a dense compound, obtained without the use of classical methods involving large amounts of cement, notes interestingengineering.
Desert sand, too fine for construction
The context in which this research appears is one dominated by ecological paradoxes. Concrete is, after water, the most used material in the world, with an annual production of over four billion tons of cement. At the same time, this production process is responsible for approximately 8% of global carbon dioxide emissions, making the construction industry one of the biggest contributors to global pollution.
On the other hand, the construction sector is heavily dependent on sand extracted from rivers, quarries and even the marine environment, resources under increasing pressure due to intensive exploitation and impact on ecosystems. This, while the deserts offer huge amounts of sand, which was, however, considered unusable in construction for a long time, due to its too fine structure and smooth granulation.
This characteristic makes it incompatible with traditional concrete, where the particles must bond effectively to form strong structures. Without this property, desert sand could not be used on a large scale, forcing the industry to continue exploiting other natural sources, with effects such as erosion and habitat degradation.
The research team analyzed whether this seemingly useless material can be transformed into a functional resource through an alternative production method that does not depend on classic cement as the main binder.
Laboratory results have shown that desert sand can acquire useful structural properties when combined with organic materials and processed under carefully controlled conditions.
How the material was obtained
“It has been debated for many years whether desert sand can be used in concrete. The problem is that it is so fine that it does not work well as a binding element in the material. In other words, the resulting concrete would not have the strength required for construction.” explained Ren Wei, postdoctoral researcher at NTNU.
To overcome this limitation, the researchers combined desert sand with plant additives and wood powder, simultaneously applying high pressure and temperature. By carefully adjusting the production parameters – including temperature, pressure, mixing proportions and process time – a compact material with a stable structure was obtained without the intensive use of cement.
All tests were performed in a laboratory environment at the University of Tokyo.
The researchers compared desert sand with other types of fine aggregate and analyzed how different factors influence the strength and density of the final material.
“We analyzed the influence of several variables on the strength and density of the material, including temperature, mix ratio, pressure, pressing time and types of sand used,” Ren Wei stated.
Potentially ecological, but low resistance
The results show that the obtained material is strong enough for non-structural uses, such as pavements or pedestrian walkways. However, researchers point out that “botanical sand concrete” is not yet ready for large-scale construction or harsh climatic conditions.
Further studies are needed to evaluate its long-term behavior, including resistance to low temperatures and prolonged outdoor exposure.
Another important conclusion of the researchers is that desert sand should be used locally, to reduce the environmental impact generated by the transport of heavy materials over long distances.
If perfected, this type of material could reduce pressure on sand mining from rivers and quarries, lessening environmental degradation while providing a practical use for an abundant resource in the world’s arid regions.
