A rectangular beam has a cross section of b = 14 in., h = 24 in., and d = 21.5 in. It is reinforced with three No. 6 Grade 60 bars. The concrete strength is 9,400 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the cracked moment of inertia, Icr. The neutral axis location of the cracked beam (measured from the top of the beam) is 4.1442 in.

A rectangular beam has a cross section of b = 16 in., h = 26 in., and d = 23.5 in. It is reinforced with three No. 6 Grade 60 bars. The concrete strength is 2,500 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the assumed modulus of elasticity of the concrete, Ec.

Heads can be attached to one or both ends of a bar by internal threads on the head mating to the bar, welding or forging onto the bar, or by a separate nut used to secure the head onto the bar.

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 = 17 in. and d = 22 in., four galvanized No. 8 Grade 60 bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 8 in. along the span. Assume 7,000-psi normal-weight concrete and a clear cover of 1.75 in.

Concrete can crack due to imposed deformations, such as differential settlement, shrinkage, and temperature differentials.

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 = 17 in. and d = 22 in., four galvanized No. 8 Grade 60 bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 8 in. along the span. Assume 7,000-psi normal-weight concrete and a clear cover of 1.75 in.

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 16 in. and d = 24 in., three epoxy-coated No. 7 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 4 Grade 60 stirrups located every 10 in. along the span. Assume 6,000-psi lightweight concrete and a clear cover of 1.75 in.

Compression-development lengths are considerably longer than tension-development lengths, because some force is transferred to the concrete by the bearing at the end of the bar.

Determine the bar-spacing factor, cb, for a simply supported rectangular beam with b = 18 in. and No. 3 stirrups. This beam has five No. 8 bars as longitudinal reinforcement. The clear cover is 1.5 in.

A rectangular beam with cross section b = 14 in., h = 22 in., and d = 19.5 in. supports a total factored uniform load of 2.20 kips/ft, including its own dead load. The beam is simply supported with a 23-ft span. It is reinforced with five No. 7 Grade 60 bars, three 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 five bars is φMn = 232.3 kip-ft, and the strength of the remaining two bars is φMn = 100.3 kip-ft. Determine the distance from the support to the theoretical cutoff point (i.e. disregard ACI 318-14 Section 9.7.3.3).