A rectangular beam with cross section b = 16 in., h = 20 in., and d = 17.5 in. supports a total factored uniform load of 3.60 kips/ft, including its own dead load. The beam is simply supported with a 18-ft span. It is reinforced with five No. 8 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 6,300 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 = 286.5 kip-ft, and the strength of the remaining two bars is φMn = 120.5 kip-ft. Determine the distance from the support to the theoretical cutoff point (i.e. disregard ACI 318-14 Section 9.7.3.3).

A rectangular beam with cross section b = 16 in., h = 28 in., and d = 25.5 in. supports a total factored uniform load of 3.50 kips/ft, including its own dead load. The beam is simply supported with a 23-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 3,600 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 four bars is φMn = 335.1 kip-ft, and the strength of the remaining two bars is φMn = 174.4 kip-ft. If the distance from the support to the theoretical cutoff point is 5.791 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).

A rectangular beam with cross section b = 14 in., h = 22 in., and d = 19.5 in. supports a total factored uniform load of 1.10 kips/ft, including its own dead load. The beam is simply supported with a 22-ft span. It is reinforced with four No. 5 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 6,600 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 four bars is φMn = 106.2 kip-ft, and the strength of the remaining two bars is φMn = 53.74 kip-ft. If the distance from the support to the theoretical cutoff point is 6.174 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).

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., three 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 6,000-psi lightweight concrete and a clear cover of 2 in.

A continuous beam’s flexural reinforcement must extend at least _____ from the point where it is no longer needed to resist tension. Assume f’c = 6,000 psi, fyt = 40,000 psi, b = 12 in., d = 18 in., and that there are four No. 8 longitudinal tension bars and No. 5 stirrups at 7 in. o.c. The stirrup hooks are 135°.

The main purpose of continuity and structural integrity reinforcement requirements is to spread localized damage to other parts of the structure and tie structural elements together.

Is the actual size of hooks critical in detailing a structure?

If φVc = 34 kip and Vu = 68 kip, are stirrups required?

Compression-development lengths are longer than tension-development lengths, because some force is transferred to the concrete by the bearing at the end of the bar and there are no cracks in such an anchorage region.

Stirrups do not preventing inclined cracks from forming.