A new innovative bitumen suspension suitable for year-round pothole repair of roads has been developed by researchers from Perm National Research Polytechnic University (PNRPU) in collaboration with MADI, ROSDORNII and the Russian Academy of Transport. The material retains its properties for up to 40 years in sealed packaging and can be used even at temperatures down to –15 °C.
Traditional asphalt concrete mixes require heating to 150–180 °C, which makes winter road repairs almost impossible. "Warm" mixes are also limited to positive temperatures, and "cold" mixes quickly lose their suitability — their shelf life does not exceed a month, and they slowly gain strength.
The new material solves these problems. It consists of 33% limestone mineral powder, 34% water and 33% viscous bitumen. During production, hot bitumen (at least 155 °C) is introduced into a mixture of cold mineral powder and water, which causes it to break down into microscopic spheres, instantly "sealed" by a mineral shell. This ensures the stability of the suspension without the use of chemical emulsifiers.
The finished composition is a pasty mass resembling wet sand. To use it, it is enough to dilute it with water and add sand with gravel in the required proportions — no heating is required.
Unlike bitumen emulsions, which are prone to delamination, the new suspension forms a stable structure due to the interaction of particles of different sizes.
