Doubly-Reinforced Beam — ACI 318-25 Flexural Design

1 · Input data

Flexural design check of a rectangular, nonprestressed, doubly-reinforced beam to ACI CODE-318-25 (procedure ENG-2026-10-025): the section, the materials, the factored moment, the exposure, the trial tension and compression bars, and the tie details. The page first works out the ceiling strength of a singly-reinforced section, says whether compression steel is required, then checks the pair of bar groups you entered by equilibrium, strain compatibility, tension control, minimum steel, detailing and development. Every parameter below is required. Press Solve the beam flexure check when the card is complete — if anything is missing or malformed the page opens a pop-up naming each parameter and computes nothing; an input that is well-formed but outside the procedure is refused with the clause that refuses it.

Section and materials

b — width of the rectangular section (in)

h — overall depth of the section (in)

f′_c — specified compressive strength of concrete (psi)

f_y — specified yield strength of reinforcement (psi)

Demand and exposure

M_u — factored moment at the section (kip-ft)

P_u — factored axial compression (kip, 0 if none)

Concrete exposure (Table 20.5.1.3.1)

Tension reinforcement A_s

Tension bar size

Number of tension bars (2 or more)

Horizontal layers of tension bars

Compression reinforcement A′_s and ties

Compression bar size

Number of compression bars (2 or more, one per tie corner)

Tie / stirrup bar size (9.7.6.4.2, 25.7.2.2)

Tie spacing provided, on center (in)

Concrete and aggregate

d_agg — nominal maximum aggregate size (in)

λ — concrete type (Table 25.4.9.3)

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2 · Solution

No solution yet — complete every input in the card above and press Solve the beam flexure check. This card stays empty until a solution is computed, and it is emptied again the moment any input changes, so a displayed solution always belongs to the inputs on screen.