The Impact of Corrosion on the Mechanical Properties of Smooth Steel Rebar HPB235 The impact of corrosion on the mechanical properties of steel rebar was examined. An experimental investigation was carried out in order to gain better insight of the effect of corrosion on the mass loss, strength, of smooth Steel Rebar HPB235 10 mm diameter steel bars that were artificially corroded for different corrosion levels. Corrosion is a negative contributor on the structural integrity of concrete structures and leads to degradation of the mechanical properties of steel rebar. In order to evaluate the influence of corrosion on the mechanical properties of steel rebar, an experimental investigation was conducted on smooth steel rebar of 10 mm diameters, and which were artificially corroded for 1, 3, 5 and 7 months. The laboratory tests suggest that corrosion duration had a significant impact on the strength degradation of the specimens. The mechanical properties of tensile test before and after corrosion indicated progressive variation and drastic drop in their values. The corrosion enhanced the damage and created pits and notches, resulting in stress concentration points and progressive reduction of strength. It gets the express formula nominal ultimate strength and nominal yield strength.