Determine the bar-spacing factor, cb, for a simply supported rectangular beam with b = 20 in. and No. 3 stirrups. This beam has three No. 8 bars as longitudinal reinforcement. The clear cover is 1.8 in.

A rectangular beam with cross section b = 14 in., h = 20 in., and d = 17.5 in. supports a total factored uniform load of 1.30 kips/ft, including its own dead load. The beam is simply supported with a 20-ft span. It is reinforced with five No. 5 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 3,600 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 = 114.5 kip-ft, and the strength of the remaining two bars is φMn = 47.61 kip-ft. If the distance from the support to the theoretical cutoff point is 4.828 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).

Determine the lightweight modification factor, λ, for a rectangular beam with b = 16 in. and d = 21 in., four galvanized No. 9 Grade 60 tension-reinforcement bars placed in the bottom of the beam, and No. 4 Grade 60 stirrups located every 8 in. along the span. Assume 6,000-psi normal-weight concrete and a clear cover of 2 in.

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 = 24 in., three uncoated No. 6 Grade 60 bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 12 in. along the span. Assume 4,000-psi lightweight concrete and a clear cover of 1.5 in.

A rectangular beam with cross section b = 16 in., h = 22 in., and d = 19.5 in. supports a total factored uniform load of 3.00 kips/ft, including its own dead load. The beam is simply supported with a 20-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 7,500 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 = 251.3 kip-ft, and the strength of the remaining two bars is φMn = 103.4 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.

Determine the bar-spacing factor, cb, for a simply supported rectangular beam with b = 16 in. and No. 3 stirrups. This beam has five No. 8 bars as longitudinal reinforcement. The clear cover is 1.8 in.

When the force in a reinforcing bar changes from point to point along its length, there must be bond stresses between it and the concrete.

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 = 23 in., three epoxy-coated No. 6 Grade 60 bars placed in the bottom of the beam, and No. 4 Grade 60 stirrups located every 12 in. along the span. Assume 7,000-psi lightweight concrete and a clear cover of 1.75 in.

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