Optimizing concrete strength through pozzolan variation, heat treatment, and alkaline solution modulation: A comprehensive study

The study aimed to assess concrete characteristics and mechanical properties by incorporating pozzolan variations, heat treatments, and alkaline solution molarities. It focused on identifying the optimal pozzolan addition percentage for achieving maximum concrete strength. Specimens underwent heat treatments at 60°C, 90°C, and exposure to alkaline solutions with molarity levels of 6M for rice husk ash and 8M for palm shell ash (PSA). Compressive strength testing at 28 days revealed the most optimal strength of 25.80 MPa in concrete without heat treatment, with 10% Palm Shell Ash pozzolan addition. Non-pozzolan concrete subjected to 1 day of 90°C heat treatment exhibited a strength of 21.99 MPa. The lowest strength observed in concrete without heat treatment, with 15% rice husk ash, resulting in 12.50 MPa. FTIR analysis focused on the chemical aspects of concrete, particularly changes in molecular structure due to different parameters. Composite concrete samples incorporating rice husk ash pozzolan and varying alkaline solution concentrations showed negligible differences. Further analysis found that mixing concrete with 15% Palm shell ash without heat treatment resulted in optimal compressive strength of 22.60 MPa, highlighting PSA's potential in increasing concrete strength. The research also emphasized the effect of temperature on concrete strength, with non-pozzolan concrete heated at 90°C for 1 day showing decreased strength. Comparison of pozzolan influence revealed that Rice Husk Ash tended to reduce concrete strength, especially at higher percentages, indicating a different response to pozzolan types. FTIR analysis identified chemical components in Rice Husk Ash (RHA) pozzolan concrete, laying the foundation for understanding pozzolan-concrete matrix interaction. However, further analysis needed for accurate interpretation of FTIR results and understanding the mechanism behind pozzolan's influence on concrete strength.