Influence of Rheological Active Additives on the Properties of Self-compacting Concrete

The effect of rheological-active additives on the properties of cement suspensions and self-compacting concrete mixtures have been studied. In order to increase the rheological matrix and provide high fluidity, stone powders were used during the crushing of local mountain rocks in self-compacting concrete. Taking into account the high dispersion of rheological-active additives, highly effective plasticizers were used to regulate the reotechnological properties of cement-based mixtures. The effect of sulfonaphthalen-formaldehyde oligomer and polycarboxylate-based hyperplasticizer on rheological properties of cement systems as plasticized additive on methodology proposed by V Kalashnikov was evaluated. The flow rate of cement suspension is determined by means of mini-viscosimeter, spreading of cement-sand mortar by means of Hegermann cone, and the slump of concrete mixture by means of Abraham’s cone. On the basis of obtained results, it was determined that limestone powder was more efficient than other stone powders. Thus, when adding 40% limestone powder to the mixture, the compressive strength of the samples taken from self-compacting concrete mixture increases by 15%–30% compared to the control samples. The optimal quantities of rheological-active additives and plasticizers have been identified and the possibility of obtaining high-strength self-compacting concrete based on them has been confirmed.