Investigation of Thermal and Strength Properties of a Novel Composite Developed for Insulation as Building Material

The aim of the present study is to produce novel developed composite materials which provide thermal insulation by using waste and natural materials in construction applications. Composite construction samples were prepared using an expanded perlite aggregate of 15 % wt., 30 % wt., and 45 % wt., which had the grain sizes of 0–3 mm, 3–5 mm and 5–8 mm, as well as waste marble dust of 5 % and 15 % filtrated from a 300 µm sieve, combined with molten tragacanth of 0 %, 0.5 % and 1 %, and CEMI 42.5 N-type portland cement. The microstructure of the composite samples was examined by the SEM analysis. Density, thermal conductivity, compressive strength, abrasion loss, water absorption, compressive strength after high temperature, and compressive strength after freeze–thaw tests were performed on these composite samples. It was found that the density values of composite materials decreased from 1.983 g·cm−3 to 0.933 g·cm−3. It was observed that their porosity ratios up to 43 % were improved by increasing the amount of waste marble dust, expanded perlite and molten tragacanth, additionally, while their compressive strengths decreased. Thermal conductivity of the porous samples decreased from 0.468 W·m−1·K−1 to 0.167 W·m−1·K−1 by raising their porosity, which corresponds to a reduction of 36%. It was observed that as the rates and sizes of the materials used in the samples, their thermal conductivity, compressive strength and density values decreased, and the abrasion loss and water absorption increased.