NUST MISIS, in cooperation with PJSC Severstal, proposed to produce concrete from waste generated at various stages of metallurgical production. The proposed technology is suitable for road construction in harsh climatic conditions, for example, in the Arctic. This was reported to socialbites.ca at NUST MISIS.
Two binders are commonly used in concrete production: cement and bitumen. The first produces gray concrete and the second produces asphalt concrete. However, cement production is highly unecological and very costly. Scientists have proposed a new approach: using blast furnace slag heaps as binders. This is the waste left after iron and steel production.
According to scientists, the technology will reduce the energy intensity of cement production by more than half – to 2.3 GJ per ton instead of 5-8. Reducing energy intensity not only helps reduce greenhouse gas emissions, but can also solve the problem of waste disposal. Also, the cost will be lower.
“To determine the corrosion properties, a laboratory stand was built that allows simulating the conditions for finding concrete products in seawater for accelerated testing, as corrosion of cement stone can take several years. The model specimens have been on the pier for more than 2 years and in the variable water level region (during the change of seasons the specimens were either above the water surface or underwater) and their strength is only increasing. During the first tests, carried out 5 months after the production of the samples, the compressive strength of concrete was 10-20 MPa, at the moment the strength is already 25-30 MPa, ”says the co-author. The study, an employee of the department, NUST MISIS Bekzod Khaydarov, Functional nanosystems and high-temperature materials told socialbites.ca.
According to the researchers, the ultimate goal of the project is the development of mineral slag binders and slag concretes for port and civil infrastructure construction in the Arctic region.