Abstract
Most concrete structures are reinforced with steel bars to enhance their performance. However, engineers face two major challenges: the high cost of steel compared to concrete and congestion of reinforcement, especially in beams and beam-column joints. These issues can largely be mitigated by using high-strength (HS) steel instead of normal-strength (NS) steel. This study investigates twelve concrete beams (150 × 250 mm), divided into three groups of four specimens. The first group was reinforced with NS steel bars, the second with HS steel, and the third with a combination of both. All beams were tested under four-point bending over a clear span of 2000 mm. Grade 1860 steel (G-270) was used for the HS steel reinforcement. Results showed that achieving the same flexural strength required nearly three times more NS steel than HS steel, leading to reduced reinforcement congestion, lower material usage, and decreased labor costs. Beam specimens were reinforced with steel contents of 1.80 kg/m (NS steel), 1.76 kg/m (HS steel), and 1.66 kg/m (combined reinforcement). Beams with HS steel showed significantly higher ultimate load capacity and improved stiffness (load-deflection behavior) compared to beams with NS steel or combined reinforcement. The analysis confirmed that the applied design method offers conservative and reliable predictions.