BINDING COMPOSITIONS USING VERMICULITE FOR HEAT PROTECTIVE SOLUTIONS

Abstract

The study of cement mortars containing expanded vermiculite as a filler is presented. The use of vermiculite up to 30% or more leads to good thermal insulation properties of solution, but low compressive strength. Features of the nature of expanded vermiculite contribute to reducing the density and providing heat-shielding properties. Mechanical activation of binder compositions depending on the duration of treatment in a vibrating mill compositions: Portland cement 90-70%, vermiculite 10-30%, allow to obtain a density in the range of 1720-1933 kg/m3, with a strength of 42.8-58.2 MPa, while saving up to 10 - 20% of expensive energy-intensive cement. Cement stone from binder compositions is created due to the form ation of a spatial framework created by a porous mineral filler, which, due to its high dispersion, occupies a significant spatial volume and a crystalline structure is formed on this mineral filler, as on substrates, created by calcium hydrosilicates and hydroaluminates. It builds up a secondary framework with crystalline neoplasms on finely dispersed vermiculite grains - plates. The developed binder has a porous structure due to the introduction of vermiculite filler, which reduces the thermal conductivity of the created composite. The use of the resulting binder compositions prepared from a mixture of Portland cement and vermiculite, in combination with a porous filler - expanded vermiculite, allows obtaining a heat-insulating mortar with high heat-shielding performance and guaranteed strength