Optimizing building insulation with silica nanoparticles: a study on lime-based roof and screed pastes for enhanced compressive strength and thermogravimetric analysis

Research into leveraging nanomaterials to enhance building material performance has shown significant progress in recent decades. Silica nanoparticles (SiO2), a prevalent chemical element in ceramics, glass, sand, cement, and binders, have been a focus. This study delved into the impact of varying nanosilica (NS) percentages (ranging from 0 to 2.5% of LRP weight) on lime-based pastes for roofs and screeds (LRP), commonly used in building insulation. Specimens underwent demolding after 48 h, with 75% treated at 40, 60, and 80 °C for 7 h and then cured at room temperature for 3, 7, and 28 days. Analysis revealed that SiO2 and CaO in LRP transformed into calcium silicate and calcium carbonate during hydration. The addition of NS notably enhanced compressive strength by facilitating calcium silicate formation and reducing pore structures, with the best results at 40 °C. Thermogravimetric analysis indicated a significant weight loss reduction (2.3 times less) in samples with 2.5% NS content compared to those without. Optimal NS content percentages of 1.5% and 2.5%, replacing LRP at water/binder ratios of 0.6 and 0.75, respectively, were identified based on tensile and compressive strengths and desirable flowability.