According to IS 456:2000, the Indian Standard code of practice for plain and reinforced concrete, the reinforcement detailing requirements for beams include the following:
Minimum Reinforcement: Beams should have minimum reinforcement provided in accordance with the specified design requirements. The minimum reinforcement is expressed as a percentage of the cross-sectional area of the concrete.
Spacing and Cover: The spacing between the reinforcement bars in beams should be such that it allows the concrete to surround and protect the reinforcement adequately. The minimum cover, which is the distance between the outer surface of the concrete and the nearest reinforcement, should also be maintained as per the design requirements.
Beam Width and Depth: The dimensions of the beam, including its width and effective depth, should be determined based on the structural design calculations. These dimensions are essential for determining the quantity and arrangement of reinforcement in the beam.
Reinforcement Distribution: The reinforcement in beams should be distributed in a manner that provides adequate strength and ensures proper load transfer. This typically involves providing both top and bottom reinforcement, with the bottom reinforcement being greater in quantity to resist tension forces.
Flexural Reinforcement: The main flexural reinforcement in a beam consists of longitudinal bars (bottom reinforcement) that resist tensile forces resulting from bending moments. These bars are typically placed at the bottom of the beam and extend over the span length.
Shear Reinforcement: Shear reinforcement is required in beams to resist the shear forces that act perpendicular to the longitudinal axis of the beam. This reinforcement typically includes stirrups or bent-up bars placed at suitable intervals along the length of the beam.
Bar Bending Shapes: The bending shapes, including bends, hooks, and curtailments, should be provided as per the design requirements. These shapes ensure proper anchorage and continuity of reinforcement.
Lap Length and Splicing: Where required, lap lengths should be provided for the splicing of reinforcement bars. The lap lengths are determined based on the diameter of the bars, the grade of the reinforcement, and the specified bond strength.
It's important to note that the above guidelines are a summary of the reinforcement detailing requirements for beams as per IS 456:2000. For detailed and accurate reinforcement detailing, it is crucial to refer to the complete code and consult with a structural engineer or industry professional who is knowledgeable about the current version of the Indian Standard and any subsequent amendments.