Heat-insulating foam-silicate materials

Abstract

Purpose: The aim of this work is to study the density, thermal conductivity and strength of insulating materials and fine-grained concrete based on cement binder with the use of foamed silicates. Vermiculite from Tatarsky deposit (Krasnoyarsk region), perlite from Khasynsky (Magadan region) and Mukhor-Talinsky (Republic of Buryatia) deposits, and tripoli from Potaninsky deposit (Chelyabinsk region) are used to obtain porous fillers.Research findings: It was found that the strength of materials based on cement binder and foamed silicates is determined by the strength of hydrated cement, aggregate, and contact zone of hydrated cement and filler. The coefficient of thermal conductivity of insulating materials based on foamed granules of natural dispersed raw materials (vermiculite, perlite, tripoli) with cement (23.5 vol. %) ranges from 0.112 to 0.181 W/(m·deg), which is 1.5–1.6 times higher than thermal conductivity of the granular layer.Compressive strength of the obtained materials ranges between 2.0 and 4.0 MPa. Compressive strength of lightweight concrete with the silica sand content of 32 vol.% and plasticizer, increases up to 8.5 MPa in compositions with vermiculite and up to 9.4 MPa in compositions with perlite from Mukhor-Talinskoe deposit.Depending on the quartz sand content, the density of concrete with foamed vermiculite and foamed perlite varies from 1100 to 1400 kg/m3 and from 1300 to 1600 kg/m3, respectively. Thermal conductivity of concretes with minimum density is 0.193 W/(m·deg) in the composition with vermiculite and 0.286 W/(m·deg) in the composition with perlite. At the maximum density of fine-grained concrete, the thermal conductivity increases to 0.277 and 0.411 W/(m·deg), respectively.