Synergistic Effects of Rice Husk Ash and Pumice Powder as Supplementary Cementitious Materials in Blended Cement Concrete.

The increasing need for sustainable construction materials has heightened research on supplementary cementitious materials that can partially substitute ordinary Portland cement in concrete production. This study examines the mechanical properties of blended cement concrete that includes rice husk ash (RHA) and pumice powder (PP) as partial substitutes for cement. Concrete mixtures were formulated with differing ratios of RHA and PP, and their density, compressive strength, and flexural strength were assessed during curing durations of ۷, ۱۴, and ۲۸ days. Standard testing protocols were implemented to ascertain the mechanical properties of the concrete specimens, while statistical analyses, encompassing regression, correlation, and analysis of variance, were utilised to assess the relationships among the obtained parameters.The results indicated that the density of the concrete mixtures generally increased with curing age due to continued hydration and improved packing of the cementitious matrix. However, slight variations in density were observed as the replacement levels of RHA and PP increased. Compressive and flexural strength results showed that the control mix achieved the highest strength values, while mixtures containing higher proportions of supplementary cementitious materials exhibited reduced compressive strength. This reduction is attributed to the dilution effect associated with reduced clinker content and the slower pozzolanic reaction of the replacement materials at early curing stages. Nevertheless, moderate replacement levels demonstrated satisfactory mechanical performance. Correlation analysis further revealed strong positive relationships between density, compressive strength, and flexural strength. The study demonstrates that RHA and PP can be effectively utilised as supplementary cementitious materials in concrete production.

کلیدواژه ها:

Rice Husk Ash ، pumice powder ، Supplementary cementitious materials ، blended cement concrete ، and sustainable construction