What does the symbol I​g ​represent in the transition from I​g​ to I​cr ​equation?

Epoxy-coated or galvanized reinforcement is used to increase corrosion problems.

A simply supported beam with dimensions of b = 14 in., h = 28 in., d = 25.5 in., and L = 23 ft supports a uniform service (unfactored) dead load of 1.708333 kips/ft including its own self weight plus a uniform service (unfactored) live load of 0.8 kips/ft. The beam is reinforced with four No. 7 Grade 60 bars. The concrete strength is 3,700 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Using the effective moment of inertia, determine the immediate mid-span deflection of the beam due to the combined service loads (dead plus live).The effective moment of inertia Ie = 9,728.2 in.4.

Determine the size modification factor, ψs, for a rectangular beam with b = 18 in. and d = 24 in., four epoxy-coated No. 6 Grade 60 tension-reinforcement bars placed in the bottom of the beam, and No. 4 Grade 40 stirrups located every 12 in. along the span. Assume 4,000-psi normal-weight concrete and a clear cover of 1.5 in.

There are universally accepted rules for maximum crack widths.

The fatigue strength of longitudinal bars is greater than that of stirrups.

A beam is singly reinforced with the reinforcement in two rows. The bottom row contains 10 No. 8 bars at a depth of 18 in. The top row contains 6 No. 5 bars at a depth of 12 in. Determine the effective (centroidal) depth, d, of the steel.

A rectangular beam has a cross section of b = 14 in., h = 26 in., and d = 23.5 in. It is reinforced with two No. 7 Grade 60 bars. The concrete strength is 10,000 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the gross moment of inertia, Ig, for the beam.

A rectangular beam has a cross section of b = 16 in., h = 26 in., and d = 23.5 in. It is reinforced with two No. 8 Grade 60 bars. The concrete strength is 5,500 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the transformed cross-sectional area of the bars, Ast.

The fatigue strength of stirrups is less than that of longitudinal bars.