Improving the thermal insulation properties of thin-bed mortar|Part II: Effects of selected admixtures and combinations thereof on material properties, in particular pore-size distribution, thermal conductivity and compressive strength
![22 CaCO3 contents [wt.%] of a modified thin-bed mortar specimen containing 10 vol.% fumed silica compared with a thin-bed mortar zero sample after 2, 7, 14, 21 and 28 days of hardening, hydrated in air and in exclusion of CO2 (N2)](/uploads/images/2018/w300_h200_x297_y421_Materials_Krcmar2_Figure_22-7c19d6633df659c3.jpeg)
The thermal properties of thin-bed mortar can be optimized with the aid of special admixtures. Adding fumed silica, for example, reduces the thermal conductivity. The combined addition of fumed silica and expanded aluminosilicate also yields thermal optimization of thin bed mortar. Both thusly modified thin-bed mortars meet the requirements of compressive strength class M 10. The higher the pore volume ratio, the more successfully thermal conductivity can be reduced.
1 Introduction and objectives
The main objective of the subject research work was to develop a new type of thin-bed mortar characterized by reduced thermal conductivity with no loss of compressive strength. In Part I of this report [1], a series of solitarily added admixtures were screened. Thin-bed mortar components with grain sizes ≥ 125 µm were proportionately substituted by selected admixtures, and the material engineering parameters of cured thin-bed mortar samples were experimentally determined. Fumed silica, expanded perlite and expanded aluminosilicate were identified as very suitable...
