New concretes can help environment protection
Scientists from the Institute of Construction and Architecture of SAS are developing and testing new multicomponent cement aggregates using domestic natural resources and by-products of other industrial productions, or rather, waste. The result of their research is various types of concrete with extraordinary properties which can be implemented in the area of civil construction as well as in industrial applications.
As the only ones in Slovakia, these experts deal with the development of materials that can withstand extreme conditions of the environment in wells up to 10 km of depth. “Examples of the materials we develop are cement composites that can be used in geothermal or oil wells. In our tests, we expose the samples to temperatures of approximately 220°C with the composite action of water vapour pressure. Moreover, the water present in geothermal wells also contains various chemical compounds, therefore these materials must be resistant to these often corrosive substances,” explains Professor Martin Palou, Head of the Department of Building Materials and Constructions of ÚSTARCH SAV.
When studying the developed materials, the Department also uses a special air-conditioning chamber, in which samples of cement composites are exposed to CO2 gas activity. "When CO2 is applied to these samples, calcium carbonate is formed, which is, to some extent, able to fill its pores. This increases the bulk weight of the composite and improves its mechanical properties," explains Prof. Palou. His long-term goal is to develop concretes that would be in able to capture CO2 emissions in their structure to an increased extent, which would significantly contribute to reducing global warming.
The research team led by Professor Martin Palou is a key partner of an international project focused on the development and optimisation of the composition of the so-called heavyweight concretes which are able to withstand the long-term effects of ionizing radiation, for example in nuclear power plant environments, and thus contributing to the protection of human health and the environment.
Besides, researchers from ÚSTARCH SAS also deal with the development of the so-called self-compacting high-quality heavyweight concretes with a compressive strength exceeding 60 MPa. Their goal is to optimise the material composition so that additional vibration does not have to be applied when laying the liquid concrete mixture during construction work. ”These concretes contain heavyweight gravel aggregates based on barite, which we also obtain from Slovakia. This gravel aggregate has a considerable tendency to sediment in a fresh concrete mix. The modifications chosen by us in the composition of the concrete mixtures prevent the separation of the gravel aggregate component of the concrete mixture from the cement matrix. This not only ensures the required strength, but also saves time and electricity,” explains the Professor.
Edited by: Katarína Gáliková
Photo: Katarína Gáliková
Video: Martin Bystriansky