The article examines the features of dismantled paving slabs as raw materials for the production of recycled aggregate for concrete. The effect of crushed fine fractions of secondary crushed stone screenings on the properties of fine-grained self-compacting concrete was investigated. It was experimentally shown that the use of this material as a mineral additive leads to an increase in the water demand of the self-compacting fine-grained mixture and a significant decrease in strength.

Keywords: demolition waste, vibro-pressed paving slabs, recycling, screening of secondary crushed stone, mineral additive, self-compacting fine-grained concrete, consistency of concrete mix, strength, shrinkage

The importance of recycling construction waste for the development of closed-loop economy technologies in the construction industry is considered. The effect of replacing high-quality granite and limestone crushed stone with secondary aggregate obtained by crushing concrete scrap on the strength properties of geopolymer concrete was investigated. It was established that such a replacement does not lead to a decrease in the strength of such concrete, and the impact resistance increases significantly.

Keywords: demolition waste, concrete scrap, recycling, geopolymer concrete, blast furnace granular slag, crushed stone crushing screening, closed-loop economy technologies, secondary aggregate, strength, impact resistance