This study investigated the effect of corrosion on the flexural behavior and midspan deflection of reinforced concrete beam members. Control, corroded, and resin-coated concrete beam specimens were tested to determine their failure load, midspan deflection, rebar diameter measurements, and mechanical properties. The results showed that corrosion significantly reduced the flexural strength and increased the midspan deflection of beams due to weakening of the reinforcing steel. The average failure load of corroded beams decreased by 25.73% compared to the control beams. Similarly, the average midspan deflection of corroded beams increased by 103.8% over the control beams. Measurements of rebar diameters before and after corrosion revealed reductions of up to 0.87% in corroded samples, substantiating corrosion-induced thinning. Additionally, mechanical properties testing showed decreases in ultimate tensile strength, yield strength, and strain ratio while increasing ductility for corroded rebars. Resin coating prevented much of the strength loss and provided protective benefits near that of the control specimens. The relationship between failure load, midspan deflection, diameter measurements, mechanical properties and corrosion damage was investigated through analytical comparisons. Corroded samples consistently demonstrated lower failure loads, higher deflections, reduced diameters and strengths versus controls. Conversely, coated samples performed similarly to controls, validating the coating's effectiveness. This research quantitatively confirms literature reports that corrosion degrades reinforced concrete through weakening of rebar-concrete bond and steel deterioration over time if left unprotected. The findings emphasize the importance of mitigating corrosion to ensure structural integrity, safety and durability of reinforced concrete infrastructure.