Mechanical Properties of Fly Ash Blended Concrete Made With Coal Washery Rejects as Coarse Aggregate

This investigation studied the mechanical properties of concrete containing CWR at different replacement levels (0% - 50%).The values of the mechanical properties like Compressive strength test, Split tensile strength, Flexural strength, Modulus of Elasticity and Bond strength were compared to M 25 grade of conventional concrete (CC). From the results, it is revealed that 30% CWR replacement can be considered as optimum level in the construction industry. Coarse aggregate replaced with five percentages (10%, 20%, 30%, 40%, and 50%) of fly ash by weight. Tests were conducted for properties of fresh concrete (workability), and compressive strength was determined at 7, 28 and 56 days. Test results indicate significant improvement in the strength properties of plain concrete by the inclusion of fly ash as partial replacement of either fine aggregate (sand) or cement and can be effectively used in concrete structures.