Development of composition of fine-grained concrete based on ash-and-slag wastes for additive technology of manufacturing small architectural forms

Developing a fine-grained concrete composition for additive technologies is an important scientific and practical task, since traditional building mixtures are unsuitable for 3D printers, and special solutions are practically absent in mass production. This study aims to develop a composition of fine-grained concrete for additive technologies using local resources and ash and slag waste of the Ust-Kamenogorsk thermal power plant, which contributes to the expansion of the raw material base used in this area. The work was carried out taking into account the analysis of the literature review, which made it possible to identify key aspects and directions in the development of concrete mixtures for additive technologies. This article discusses the possibility of using ash and slag waste in concrete as a filler. Ash has a grain size comparable to river sand, so it can be used as a new material to replace fine filler. To obtain the mixture, 5 experimental mixtures and one reference sample were prepared. The optimal composition is considered to include 30% of M500 Portland cement, 40% of sand, and 30% of ash and slag. The physical and mechanical characteristics of this composition are as follows: the mobility of the mixture is 5.81 cm, and the setting completion time is 4 hours 19 minutes. The results of the sample tests confirmed that the created fine-grained concrete compositions are suitable for extrusion on construction 3D printers. The possibility of creating a composition based on local ash and slag waste for additive technologies used in producing small architectural forms was experimentally confirmed.