"Вестник МГСУ"

Subject: applying mineral microfillers based on technogenic waste of non-ferrous metallurgy together with nano silica in the technology of cast and self-compacting concrete is the subject of the paper. The results of the previous experiments proved the effectiveness of the use of ground copper slag in the technology of cast concrete mixtures. However, there are no research results on the combined work of the microfiller and nanoparticles in plastic concrete mixtures. Research objectives: determining the optimal range of the use of nano silica in cast concrete mixtures with copper slag filler from the viewpoint of conservation of plasticity of the concrete mixture and increase of the concrete strength. Materials and methods: plasticity of the concrete mixture was determined according to spread of a small cone on the shaking table by the method developed in NRU MGSU. The strength of concrete samples was checked according to GOST 10180-2012. Statistical processing of the obtained results was carried out by the least square method. Results: plots showing dependence of plasticity of the concrete mixture and strength of cast concrete with ground copper slag on the dosage of nanoparticles and also the influence of the dosage of superplasticizer on the indicated properties at high values of the content of nano silica were obtained. Regression equations for all specified dependencies were derived. Conclusions: it is established that the introduction of nano silica in a dosage of 0.1…0.5 % of cement weight positively affects the concrete strength when used in conjunction with copper slag and superplasticizer. The developed compositions of cast fine-grained concrete mixtures can be used in high-density reinforcement concrete structures with strict requirements for size of fillers and plasticity of the concrete mixture.