Japan: Researchers from the University of Tokyo have developed a new method for producing cement-free concrete from sand. The method reacts sand with alcohol in the presence of a catalyst, according to ChemEurope. When dehydrated, this produces tetraalkoxysilate. The research team then reintroduced water, and thus allowed the reactants to move back and forth between tetraalkoxysilate and sand. In this way, the sand particles progressively bonded together. The resulting concrete is reportedly more resilient to chemical, temperature and humidity changes than concrete produced from Ordinary Portland Cement (OPC).
In the report of the findings, researcher Ahmad Farahani wrote that various sources of sand tested suitable for use, including silica sand, glass beads and simulated moon sand. This gives the method the advantage that it is non-specific to raw materials or locations, and can be integrated into waste management.