Abstract
An experimental program is carried out to evaluate the mix design and mechanical properties of normal strength concrete (NSC) grade 40 MPa and high-strength concrete grade 60 and 80 MPa. The study investigates using silica fume to produce high-strength concrete grade 80 MPa and highlights the influence of adding steel fiber on the mechanical properties of normal and high-strength concrete. For NSC, the compressive strength is found at 7 and 28 days. While for higher strength concrete, the compressive strength is determined at 7, 28, and 56 days. The splitting tensile strength and flexural strength is determined at 28 days. Based on results, the specimens with 14% silica fume are higher compressive strength than the specimens with 10% silica fume by 21.8%. The presence of steel fiber increased the compressive strength of normal and high-strength concrete at 7, 28, and 56 days curing ages with different percentage and the steel fiber has an important role in increasing the splitting tensile strength and flexural strength of normal and high-strength concrete.