International Journal of Engineering and Technology

Improvements in fly ash based concrete strength in compression and flexural direction are the main objectives of this study. The compressive and flexure strength of concrete for various mixture proportions of concrete containing the inclusions of different percentage of polypropylene fibers from 0% to 0.3% and fly ash replacement levels at 25% , 50% of fly ash were investigated. The experimental test results showed that PP fibers possess increased extensibility and tensile strength, both at first crack and at ultimate, particular under flexural loading; and the fibers were able to hold the matrix together even after extensive cracking. The net result of all these is to impart to the fiber composite pronounced post – cracking ductility which is absence of ordinary concrete. To provide a basis for comparison, reference concrete specimens were cast without polypropylene fiber. The experimental test result showed that the addition of polypropylene fibers at 0.1% volume fraction (Vf) showed a consistent improvement in the concrete strength of 44.50 MPa and 55.50 MPa at 7 and 28 days respectively.