Mechanical Characterization of Concrete with Replaced Shell Ash Aggregates Using ANOVA and Regression Methods

The increasing erosion of river sand has documented the
emergency to use alternative materials with the environmental-friendly. The
paper examines the use of oyster shell ash (OSA) and walnut shell ash
(WSA) as artificial aggregates in concrete by partial replacement of fine
aggregates. Aggregates were made using 0, 20, 40, 60, 80 and 100 (weight
percent) OSA and WSA replacing the sand weight but keeping cement to
sand ratio of 1:2. They were applied to M25 grade concrete and allowed to
dry after 7, 14 and 28 days. The mechanical properties such as compressive,
split tensile, flexural strength, modulus of elasticity and impact resistance
were evaluated. The durability was tested by exposing to 3% hydrochloric
acid and 5% sodium sulfate solutions in 28 days. ANOVA has used for
measure the performance levels as statistically significant, and regression
analysis. The results showed best mechanical characteristics and chemical
resistance at 80% replacement and performance worsened at this point. The
research concludes that artificial aggregates based on OSA and WSA are
practical alternatives to sustainability, as they decrease the reliance on
natural resources and offer efficient waste usage.