Arctic builders have long been searching for a material that sets in the cold. A group of researchers at Novosibirsk State University has proposed a composition based on magnesium oxide and coal-fired power plant ash that continues to gain strength at minus 34 degrees Celsius. How durable it is remains an open question.
Frost interferes with ordinary cement: the water in the mixture turns to ice, chemical reactions slow down, and the structure fails to reach the required strength. The new composition works on a different principle.
The researchers ground magnesium oxide and ash together. Mechanical activation increased the reactivity of the particles, which accelerated the growth of K-struvite crystals — these create the material’s dense, strong framework. Low-grade magnesium oxide was used, and the ash served both as a component and as a way of disposing of power industry waste.
The best composition gained more than 28 megapascals in a day at room temperature. It also continued to harden in severe frost. After one day, the activated mixture was 74% stronger than the control sample, which contained neither ash nor co-grinding.
The scientists cannot yet say how the material will behave under repeated freeze-thaw cycles or how durable it is in real-world conditions. Without this data, it is too early to recommend it for critical structures.
The development shows that the problem of cold-weather concrete can be solved. If tests confirm the composition’s resilience, Arctic construction and emergency repairs will gain a material that does not fear frost, and the power industry will gain a way to put ash to productive use.
Source: Novosibirsk State University
Image: Sergey Volynkin
