Lime-diatomic mortar for finishing the walls of buildings

Introduction. At present, when performing finishing and restoration work, more and more preference is given to dry lime mixes (DBM). Wide opportunities for the production of dry lime-cement mixes are opened up by the use of diatomite, which is both a dry mix filler and an active mineral additive. Previous studies have confirmed the effectiveness of heat treatment of diatomite. After firing at 600–800оC, activity increases when interacting with calcium oxide hydrate. This is explained by the fact that at 600–800оC clay substances are dehydrated to metakaolinite, which is characterized by increased reactivity. The properties of dry mixtures and compositions based on them are affected by the particle size of the components of the dry mixture. In this regard, it is of great importance to study the influence of the dispersion of the components of the dry mixture on the formation of the structure of the finishing compositions. Materials and methods. To study the active centers of the diatomite surface, we used the indicator method for determining the distribution of adsorption centers. Determination of the compressive strength was carried out on a DOSM-3-1 dynamometer on samples 3x3x3 cm in size at the age of 28 days of air-dry hardening of the compositions. The determination of the granulometric composition of the components of the dry mixture was carried out by the method of sedimentation analysis. Adsorption was estimated from the optical density measured with a PEC photoelectrocalorimeter. To study adsorption at the “liquid-solid” interface, the initial components of the dry mixture, lime and diatomite, were used. Results and discussions. Accordingto the data obtained, it was found that a particle size reduction of the dry mixture filler leads to an increase in the strength characteristics of lime-diatomite compositions.It was found that the introduction of C-3 additive into the water favorsincreasing dispersion of hydrated lime, improving plasticity finishing mixture and improving the physical and mechanical characteristics lime-diatomaceous compositions.It is proposed to introduce sulfate additiveinto the formulation of the aluminumdry mixture. Increase in the compressive strength of the finishing composition with addition of aluminum sulfate 1.5–2 times was observed. Conclusion. It has been determined that the developed dry mixture is highly competitive, in terms of technological and operational properties,withprototype. Moreover, the production of the proposed DBM is more economical due to the use of local raw materials and domestic additives.