JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY, vol.24, no.1, pp.81-89, 2023 (SCI-Expanded)
Using ground raw perlite through alkali activation to produce various construction materials such as plaster, grouting, and concrete can provide economic and environmental advantages by reducing Portland cement consumption. It is aimed to produce cementless pastes and cementless mortars based on the alkali activation of raw perlite and standard sand for this study. Perlite and alkali activators (NaOH and Na2SiO3) were used as binding materials to produce cementless paste and mortar. In addition, aerated lightweight pastes and mortars were produced using hydrogen peroxide (H2O2) as a blowing agent. Thus, the aeration mechanism of the sample was examined, and the changes in apparent density, compressive strength, and flexural strength values were determined. At the same time, the thermal conductivity properties of aerated paste and mortars were investigated. Geopolymers in various Water/Perlite and H2O2/Perlite ratios were produced, and their thermal conductivity, apparent density, compressive and flexural strength were contrasted. The experimental finding revealed that adding 0.25% H2O2 (by mass of perlite) to the mixtures enabled the production of lightweight pastes and mortars with lower density and lower thermal conductivity coefficient without a significant loss of ultimate strength. The developed perlite based aerated geopolymer is a eco-friendly and energy efficient solution to the buildings. Based on the results, H2O2/Perlite% above 0.5% and water/Perlite% above 45% should be avoided for both paste and mortars. In order to obtain optimum results in terms of workability, strength, density, and thermal conductivity, it is recommended that the H2O2/Perlite ratio for all samples should be 0.25% and the Water/Perlite percentage should be 40%.