Basic factors influencing the thermal and strength properties of lightweight concretes gelled with starch

The article presents a comprehensive analysis of the influence of technological parameters on the properties of lightweight concrete gelled with starch, with particular emphasis on microstructure, porosity, and mechanical and thermal characteristics. The study examined composites with varied starch content, sodium metasilicate dosage, gelation temperature, and hydrated lime addition. Key properties were evaluated through a range of tests: fresh mix consistency, stability of mixtures in the initial curing phase, bulk density, compressive and flexural strength, thermal characteristics, microstructure analysis (SEM), pore size distribution (mercury intrusion porosimetry), and moisture sorption isotherms (DVS). The resulting materials featured high porosity (approximately 60–80 %), density of 560–650 kg/m³ , thermal conductivity of 0.077–0.096 W/mK, compressive strength of 2.0–3.5 MPa, and flexural strength of 0.5–1.2 MPa. Starch gelation technology offers a promising solution for producing lightweight materials with optimized insulation and structural performance. • Starch gelation used as bio-based pore-forming agent for lightweight concrete. • Achieved highly porous cement composites with porosity 63–76 % and low density. • Tuned mechanical and thermal properties by varying starch and activator dosages. • Sodium metasilicate and hydrated lime enhance strength and optimize porosity. • Porous composites rival autoclaved aerated concrete in insulation and strength.