Studies on thermo-mechanical and microstructural properties of non-autoclaved aerated concrete

Non-autoclaved aerated concrete (NAAC) is a viable option for roof insulation as it is an environmentally friendly, energy-efficient, and sustainable building material. The present study investigates the thermo-mechanical properties of NAAC for roof insulation. For NAAC, this study aims to identify the optimized mix proportions to achieve the desired aerating effect and strength by using aluminum powder, ground granulated blast furnace slag (GGBS), and sodium sulfate, and by replacing sand with waste materials such as class-F fly ash in varying percentages of 0%, 25%, 50%, 75%, and 100%. The mix with 100% sand replacement has a maximum compressive strength of approximately 1.4 MPa. Experimental studies were conducted to analyze the desirable properties of NAAC, including its compressive strength and thermal conductivity. The compressive strength (CS) of the NAAC samples varied from 0.765 to 1.4 MPa, the thermal conductivity varied from 0.165 to 0.137 W/mK, and the density varied from 540 to 580 kg/m3. The microstructural analysis of NAAC was performed using X-ray diffraction (XRD). The research results are intended to contribute to the creation of lightweight, affordable, environmentally friendly, fire-resistant, and thermally insulated building materials for use in construction.