The Effect of Astralenes on the Fire Resistance and Strength Characteristics of Concrete in a Hydrocarbon Fire

The paper presents the results of an experimental study of the effect of carbon nanostructures (astralenes) on the strength and heat-resistant characteristics of concrete under the influence of a hydrocarbon fire. The relevance of the study is due to the high emergency risk of oil and gas facilities, where the main factor in the destruction of building structures is the rapid loss of bearing capacity of concrete under intense heat exposure. The aim of the work was to experimentally evaluate the effectiveness of nanomodification of the cement matrix with astralenes to increase the residual strength of concrete during heating. Control and nanomodified concrete samples were used as research objects. The modification was carried out by adding astralenes to the aqueous phase, followed by ultrasonic treatment to ensure uniform particle distribution. Compressive strength was determined after heating using a hydrocarbon curve in a muffle furnace. The distribution of astralenes was confirmed by atomic force microscopy.It was found that the introduction of astralenes at a concentration of 0.2 vol. % provides an increase in the residual strength of concrete compared with control samples. The effect obtained is explained by the compaction of the microstructure of the cement matrix, a decrease in porosity and an increase in crack resistance under thermal influence.