Self-compacting concrete based on recycled crushed stone and organic-mineral additive

This paper presents the results of an experimental study on self-compacting concrete (SCC) incorporating recycled crushed concrete aggregate and an organic-mineral additive based on nanosilica and a polycarboxylate superplasticizer. The multi-stage “soft” crushing of concrete waste significantly improves the properties of the recycled aggregate, in particular its void content, water absorption and crushing strength, by reducing the amount of adhered cement paste. The fine fractions generated during this process are used as a dispersed filler in SCC. An organic-mineral additive was developed using a sol-gel route to ensure a homogeneous concrete mixture with enhanced stability of rheological properties. The experimental results demonstrate that SCC with a compressive strength exceeding 55 MPa at 28 days under normal curing conditions can be produced using the products of concrete waste crushing, confirming the potential of this approach for sustainable concrete construction.