Magnesia composite materials for layered products
Keywords:magnesia binders, porous filler, composite materials, variatropic structure, three-layer wall blocks, water resistance.
The article presents the results of experimental studies of magnesia composite materials of layered structure obtained from molding mixtures of various densities. The aim of the work is to synthesize and study the characteristics of three–layer magnesia materials. Molding mixtures were obtained from combined binders based on caustic magnesite and technogenic silica-containing materials. Specially synthesized porous aggregates from liquid-glass raw mixtures were used as fillers. Technological techniques of horizontal and vertical molding of three-layer products have been worked out. Composite magnesia material of three-layer variatropic structure is characterized by a density of 560 kg/m3, compressive strength of 6.1 MPa. Durability tests of layered composite materials have been carried out. Three-layer magnesia composite materials have shown satisfactory resistance in the conditions of an aqueous and aggressive salt environment. The developed magnesia material is comparable in physic-mechanical and cost parameters with an innovative block of encapsulated expanded clay. The low thermal conductivity of the developed magnesia material, equal to 0.115 W/(m·⁰c), will ensure a reduction in material and energy costs by 36.1% compared to the cement analogue.