Mechanical Properties and Stress-strain Relationship of Slag and Fly Ash-based One-part Geopolymer Concrete Cured at Ambient Conditions

This study explores the mechanical properties and stress-strain behavior of slag and fly ash-based one-part geopolymer concrete (OPGC) cured under ambient conditions. Twelve mix designs (M1-M12) were designed by varying the key parameters of binder quantity (350-500 kg/m3), water-to-binder (W/B) ratio (0.35-0.45), and aggregate proportions to study their effects on workability, strength, and elasticity. The compressive strength tests revealed that it ranged between 27 to 43 MPa. Strength was found to improve with increased binder quantity and reduced W/B ratio at the end of 28 days. Split tensile strength increased from 1.22 MPa to 3 MPa over the same period, following a similar trend. Young's modulus, an important indicator of material stiffness, increased from 8.7 GPa to 10.6 GPa with increased binder content and reduced W/B ratio. Slump values varied between 82 mm and 148 mm, which is more than sufficient for structural applications. These results underpin the sustainability and high performance of ambient-cured OPGC as a substitute material in place of traditional Portland cement concrete, thus offering a feasible solution toward reducing carbon emissions in the construction industry. Such a study renders a vast understanding of the mechanical behavior and the workability of OPGC, opening avenues for further acceptability in structural uses.