MECHANICAL AND MICROSTRUCTURAL CHARACTERIZATION OF ECO-FRIENDLY GEOPOLYMER MATERIALS

• Dr. Lukas Reinhardt

  Department of Materials Engineering, University of Bremen, Germany

  Author

Geopolymers have emerged as sustainable alternatives to ordinary Portland cement (OPC) due to their low carbon footprint and ability to utilize industrial by-products such as fly ash, slag, and red mud. This study investigates the mechanical performance and microstructural evolution of fly ash–slag blended geopolymers activated using sodium silicate and sodium hydroxide solutions. Compressive strength, flexural strength, porosity, and microstructural phases were evaluated using standardized testing protocols. The study further examines the influence of activator concentration and curing temperature on material behavior. Results demonstrate that the optimal blend of 70% Class F fly ash and 30% GGBS (Ground Granulated Blast Furnace Slag) activated with an 8M NaOH solution produced the highest compressive strength of 62.4 MPa at 28 days. Microstructural analysis using SEM and XRD revealed dense N–A–S–H and C–A–S–H binding gels responsible for enhanced mechanical properties. The findings indicate that geopolymer composites can offer high strength, environmental sustainability, and competitive performance compared to traditional cementitious materials.

• pdf

This work is licensed under a Creative Commons Attribution 4.0 International License.