A simply-supported beam has a 1 kip/ft uniformly-distributed load over the entire 12-ft span. What is the magnitude of the shear force at midspan?

Use ACI 318-14 Table 25.4.2.2 to determine the development length for the straight tension bars (no hooks) in a rectangular beam with b = 16 in. and d = 21 in., five uncoated No. 7 Grade 60 bars placed in the bottom of the beam, and No. 3 Grade 60 stirrups located every 10 in. along the span. Assume 5,000-psi lightweight concrete and a clear cover of 1.5 in.

Determine the lightweight modification factor, λ, for a rectangular beam with b = 18 in. and d = 23 in., five galvanized No. 7 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 6 in. along the span. Assume 8,000-psi normal-weight concrete and a clear cover of 1.75 in.

Once a splitting crack develops, bond strength rapidly drops unless there is reinforcement designed to restrain opening of the crack.

A rectangular beam with cross section b = 14 in., h = 20 in., and d = 17.5 in. supports a total factored uniform load of 3.20 kips/ft, including its own dead load. The beam is simply supported with a 19-ft span. It is reinforced with four No. 8 Grade 60 bars, two of which are cutoff between midspan and the support and two of which extend 10 in. past the centers of the supports. The concrete strength is 3,300 psi (normal weight). The beam has Grade 60 No. 3 stirrups satisfying ACI 318-14 Sections 9.7.6.2.2 and 9.6.3.3. The strength of the four bars is φMn = 214.5 kip-ft, and the strength of the remaining two bars is φMn = 115.8 kip-ft. Determine the distance from the support to the theoretical cutoff point (i.e. disregard ACI 318-14 Section 9.7.3.3).

Stirrups or ties perpendicular to the axis of the member are the most common type of web reinforcement.

Use ACI 318-14 Table 25.4.2.2 to determine the development length for the straight tension bars (no hooks) in a rectangular beam with b = 18 in. and d = 23 in., four uncoated No. 7 Grade 60 bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 10 in. along the span. Assume 4,000-psi normal-weight concrete and a clear cover of 1.75 in.

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

In a welded splice, the force in one bar is transferred to the concrete, which transfers it to the adjacent bar.

Determine the size modification factor, ψs, for a rectangular beam with b = 18 in. and d = 23 in., three uncoated No. 7 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 40 stirrups located every 8 in. along the span. Assume 4,000-psi normal-weight concrete and a clear cover of 1.75 in.