Researchers at the Swiss Federal Laboratory for Materials Science are developing technology for alternative concrete and asphalt mixtures. The main idea is to eliminate bitumen and similar hydrocarbon-based binders from the composition in order to reduce the stress on the ecosphere. Instead, stones and gravel are proposed to be fastened together using thread patterns.
The thread used in the material is the most common, which is approved in Switzerland for packaging waste paper packs. It is cheap, simple, safe and easy to recycle. It is not very strong, but this is compensated by a special weaving pattern along which the robotic hand spreads the thread. The stones are not tied in the literal sense; instead, the thread and gravel are stacked in layers, interlocking with each other.
An experimental concrete mass 80 cm high, consisting of dozens of such layers, withstood a vertical load of 22 tons. To simulate asphalt, the thread and gravel were laid out in five layers, which allowed them to withstand a load of 550 kg before the stones began to move dangerously. Now the scientists want to test the material under dynamic loading, and then start modeling and finding the optimal pattern and width of the cells for future road networks.