Determine the lightweight modification factor, λ, for a rectangular beam with b = 16 in. and d = 23 in., five galvanized No. 8 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 8 in. along the span. Assume 6,000-psi normal-weight concrete and a clear cover of 2 in.

Determine the size modification factor, ψs, for a rectangular beam with b = 16 in. and d = 23 in., three galvanized No. 6 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 40 stirrups located every 12 in. along the span. Assume 8,000-psi normal-weight concrete and a clear cover of 2 in.

A simply supported beam with dimensions of b = 16 in., h = 26 in., d = 23.5 in., and L = 18 ft supports a uniform service (unfactored) dead load of 2.133333 kips/ft including its own self weight plus a uniform service (unfactored) live load of 1.0 kips/ft. The concrete is normal-weight concrete. The beam is reinforced with 3 No. 5 bars. The concrete strength is 3,100 psi, and the yield strength of the reinforcement is 60,000 psi. Determine the maximum applied bending moment due to the combined service loads (dead plus live), Ma.      

A large stress concentration, possibly leading to large inclined cracks, happens when a tension bar is cutoff at a location of low shear force.

In a reinforced concrete beam, the flexural compressive forces are resisted by _______, while the flexural tensile forces are provided by _______.

Development length is the longest length of bar in which the bar stress can increase from zero to the yield stress.

The development length for a hooked bar is generally longer than that for a headed bar.

Hooks are used to provide additional anchorage when there is insufficient straight length available to develop a bar.

A smooth bar embedded in concrete develops bond by _______ between the concrete and the bar and by a small amount of _______.

In a pull-out test, a concrete cylinder containing the bar is placed on a stiff plate and a jack is used to push the bar into the cylinder.