This study focuses on studying the impacts of applying various content of polypropylene fiber with (2,3,4%) volume fraction. In addition, 50% fly ash (F.A.), 50% silica fume (S.F.), and (25%F.A.+ 25%S.F.) as partial substitutes for cement were used in ECC. ECC specimens were evaluated based on their workability, compressive strength, and flexural strength. The best outcomes from the mixes were compared to steel reinforcement in slabs. Three slabs were constructed: (i) slab reinforcement with steel, (ii) slab with ECC only and (iii) slab reinforcement with ECC in the tension zone. Flexural tests were carried out on slabs to determine their mode of failure and ductility. The results showed that concrete with 3.0% Vf of fiber and 25%F.A. + 25%S.F. substitution of cement had higher results in compressive strength and flexural strength, which achieved 62 MPa and 2.49 MPa, respectively. Although this concrete mix reduces workability, it requires being cast in a slab. For the slabs, the R.C. slab had the highest load carrying capacity. The failure modes of the ECC composite slabs were more ductile than the R.C. slab.