Modified heat-insulating binder using jet-grinded waste of expanded perlite sand

Abstract

The direction of many leading states is aimed at the development of the Arctic, so the creation of new generation thermal insulation materials is given priority. The novelty of the paper is to identify the scientific patterns of the influence of binder composites based on Portland cement and waste of expanded pearlite sand during joint jet grinding on the hydration mechanism and the structure of the plaster mortar. The grinding of heat-insulating binders in ball, vibration and vortex jet mills was studied. The features of hydrated phase formation and hardening of modified binders were studied taking into account the chemical, structural and morphological features of perlite wastes. Besides, the microstructural, morphological and thermal properties of the hardened binders at 28 days of curing were determined. For the first time, the scientific data were obtained on the properties of modified heat-insulating binder and plaster mortars based on it, obtained by mechanochemical jet activation. The results indicate that the jet activation of the modified binder based on Portland cement, waste from the production of expanded perlite sand and superplasticizer, contributes to the improvement of the physicomechanical properties of 28-days hardened binder: the compressive strength of 84.2 MPa and density of 2100 kg/m3. Based on the developed modified binder, the effective heat-insulating plaster mortars with heat conductivity of 0.051–0.059 W/(m·°C), a density of 240–260 kg/m3 and a compressive strength of 1.3–1.43 MPa were obtained, which meets the requirements. Technological route for the production of low-density plaster thermal insulation mix was developed.