FLEXURAL CAPACITY OF CONCRETE BEAMS REINFORCED WITH HIGH-STRENGTH STEEL BARS UNDER MONOTONIC LOADING

Abstract

This paper presents the flexural capacity of reinforced concrete beams designed with high-
strength steel bars. Reinforced concrete beams with steel bars fy = 550 MPa are designed to have flexural
strength like beams with steel bar fy 420 MPa. According to ACI 318M-19, the high-strength steel bars (fy =
550 MPa) are allowed to use as the reinforcing steel, which previously unpermitted. This study was conducted
to represent the possibility of using high-strength steel bars as reinforcement. There are five sample beams that
design with various diameters (13 and 19 mm) and strength (fy 420 and 550 MPa) of longitudinal reinforcement.
These beams were placed on two simple supported and undergo monotonic loads at two points-load. It is
reviewed the flexural capacity of beams with high-strength steel bars involve load capacity, moment, and beam
deflection. Also, the behavior of beams when receiving loads in terms of the relationship between load and
deflection. Based on the research, beams with a high-strength steel bar can accept higher loads than normal
beams by a difference of about 16-18%. While at the same deflection condition, which is 100 mm, beams with
high strength reinforcement can achieve a higher load of around 18 percent. Beam with high-strength steel bars
showed flexural behavior that was not much different from the normal-strength steel bars because it did not
show brittle collapse. It proves that high-strength steel bars can be used on reinforced concrete structural
elements if it satisfies the requirements specified in the code.