Concrete is straining the planet’s sand supplies, but researchers in Norway and Japan have found a way to turn fine desert sand into strong paving stones. Their plant-based “botanical sand concrete” could ease pressure on rivers and mountains while tapping an overlooked resource.
Concrete is everywhere: in homes, schools, bridges and sidewalks. But the world’s favorite building material depends on a resource that is running short in many places — the right kind of sand.
As demand for concrete rises, researchers are racing to find more sustainable ingredients. A team from the Norwegian University of Science and Technology (NTNU) and the University of Tokyo now believes one answer may lie in a surprising place: the world’s deserts.
They have developed a prototype material, called botanical sand concrete or botanical sandcrete, that turns fine desert sand into strong paving stones by combining it with plant-based additives and heat. The approach could help ease pressure on rivers and mountains that are currently mined or crushed to supply construction sand.
Concrete is the most widely used building material on Earth, second only to water in total consumption. Producing the cement that binds concrete together generates a large share of global carbon dioxide emissions, and the industry also drives massive sand extraction. To get sand with the right size and shape for concrete, companies crush rock into gravel and sand or dig sand from rivers and other natural deposits, reshaping landscapes and damaging ecosystems.
At the same time, deserts hold vast quantities of sand that construction companies typically ignore. The grains are so fine and smooth that they do not work well in conventional concrete mixes. For years, engineers have wondered whether that desert sand could somehow be put to use.
“Researchers have discussed for many years whether desert sand can be used in concrete. The challenge is that desert sand is so fine-grained that it is not suitable as a fastener in concrete. In other words, the concrete will not be hard enough to be used in various construction projects,” first and co-corresponding author Ren Wei, a postdoctoral fellow in NTNU’s Department of Manufacturing and Civil Engineering, said in a news release.
Instead of trying to force desert sand into standard concrete recipes, the NTNU–Tokyo team designed a different kind of material. Their botanical sand concrete is made by pressing desert sand together with tiny pieces of wood and other plant-based components under heat. The plant material helps bind the sand grains into a solid block.
In their experimental study, published in the Journal of Building Engineering, the researchers tried many combinations before landing on a formula that worked well.
“All the experiments so far have been carried out in the laboratory at the University of Tokyo. We tested how various factors affect the strength and density of the materials, including temperature, mixing ratio, pressure, pressing time and different types of sand,” Wei added.
By systematically varying those conditions, the team found that desert sand, when processed this way, can form a surprisingly strong material. In fact, the prototype blocks were robust enough to be used as paving stones for pavements and walkways.
That is a narrower use than full structural concrete, which must support heavy loads in buildings and bridges. But even focusing on pavements and similar applications could make a difference. Cities and towns around the world lay down huge areas of sidewalks, plazas and paths, all of which currently rely on conventional concrete, bricks or stone.
If botanical sand concrete can be scaled up for these uses, it could reduce the need to blast and crush rock or dredge riverbeds for sand. That would mean fewer scars on mountainsides, less disruption to river ecosystems and a more efficient use of the planet’s natural resources.
The approach could also help address challenges in desert regions, where sand is abundant but often seen as a problem rather than a resource. Turning this material, sometimes dismissed as “useless,” into building blocks for local infrastructure could support more sustainable development in those areas.
The process itself is relatively straightforward, according to the researchers.
“The production process is relatively simple, so in principle the material can be made in many places. But we need to test more, including how it can withstand cold, before it can be used out in Norway,” added Wei.
That next phase of testing will be critical. So far, all work has been done in controlled laboratory conditions. Before botanical sand concrete can be used outdoors in real-world projects, engineers will need to understand how it handles freezing temperatures, moisture, long-term wear and other environmental stresses. The team is also considering where the material makes the most environmental sense.
For the idea to deliver real climate and ecological benefits, Wei stressed that desert sand should be used close to where it is found. Shipping heavy sand or finished blocks around the world would add emissions and undercut the sustainability gains. The vision is for local or regional production, especially in areas that already have large desert sand resources.
Botanical sand concrete is still in its early stages, and it is not a direct replacement for all traditional concrete. But it points toward a broader shift in construction: using more plant-based binders, tailoring materials to local resources and designing for lower environmental impact.
If further testing confirms its durability and performance, this desert-sand-based material could become part of a new generation of greener building products. In doing so, it might help resolve a striking global paradox: while humanity is busy crushing mountains and emptying rivers for sand, vast seas of fine grains lie largely untapped in the world’s deserts.