Heat-Insulating foam concrete without autoclave hardening from local non-metal mineral raw

Abstract

Relevance: One of the priority areas for improving the energy efficiency of the enclosing structures of buildings and structures is the use of heat-insulating products made of cellular concrete. In this regard, foam concrete produced by energy-saving technologies and characterized by low density, thermal conductivity and high performance properties (strength, water resistance, etc.) is very relevant and promising. The aim of the work is to substantiate the possibility of obtaining a heat-insulating material of a cellular structure - foam concrete without autoclave hardening using finely ground bentonite clay and binders as a base: Portland cement, colloidal nanodispersed sodium polysilicate with a silicate module of 6.5 and modifier "DS-35" (patent) using foam based on a foaming agent - alkyl sulfates with a density of 1.0-1.2 g/cm3. Methods. To obtain reliable data in the study of the properties and technological parameters of the components of the mixture, and on their basis of the heat-insulating material, modern methods of testing the physical and mechanical characteristics, regulated by the relevant GOSTs, were applied. Comprehensive physical and chemical studies were carried out by X-ray, differential thermal and petrographic analyzes of non-metallic mineral raw materials. To perform complex physical and chemical studies, X-ray, differential thermal and petrographic analyzes of non-metallic mineral raw materials were carried out. Results. Conducted theoretical and experimental studies have shown the possibility of obtaining heat-insulating foam concrete without autoclave hardening using energy-saving technology, which is characterized by high performance properties, which make it possible to increase the energy efficiency of building envelopes and structures. The optimal compositions for the manufacture of heat-insulating foam concrete, which contain wt. %: cement 24.45-27.85; finely ground bentonite clay 24.45-27.85 and with a specific surface area of 2500-3000 cm2/g; colloidal nanodispersed sodium polysilicates 2-4; modifier "DS-35" 0.43-0.49; foaming agent 0.30-0.75; water 42.97-44.46. A method for manufacturing heat-insulating foam concrete from the above composition has been developed.