Sustainable Chemistry and Pharmacy, cilt.41, 2024 (SCI-Expanded)
Geopolymer concretes have great potential in the sustainable construction industry in the future, as they can be produced without using cement and waste materials can be used as binders. This paper explores the use of sustainable, lightweight geopolymer pastes as construction materials using raw perlite as the primary ingredient. It achieves this by alkaline activation with additives such as waste aluminum lathe (Al), Hydrogen peroxide (H2O2) and silica fume (SF). The experiments were conducted in four groups: Al added in the 1st group, Al + Silica fume (SF) in the 2nd group, H2O2+SF in the 3rd group, and Al + H2O2 in the 4th group. Apparent density, compressive strength, flexural strength, and thermal conductivity tests were performed at 7, 14, and 28 days. SEM and EDX analyses were also conducted. The results showed that as the ratio of Al and H2O2, which have a aerating effect, increased, decrease in apparent density and strength was observed. However, when Al + SF were added together, significant improvements of 10%–20% were observed in compressive and flexural strengths, as well as apparent density. 35% water/pearlite ratio and 0.50% Al addition reduced compressive strength by 5% and lightened apparent density by 15%. At 40% water/pearlite ratio, 0.50% Al addition reduced compressive strength by 10% and lightened apparent density by 5%. According to these results, the best performance is obtained with 35% water/pearlite ratio and 0.50% Al addition Furthermore, the addition of lightweight SF resulted in good geomerization and reduced crack formation. This effect was evident in the internal structure based on SEM analysis. Interestingly, despite aluminum's overall high thermal conductivity, its incorporation into raw perlite-based pastes resulted in reduced thermal conductivity.