A simply-supported beam has a 3 kip/ft uniformly-distributed load over the left half of its 13-ft span. What is the magnitude of the shear force at midspan?

As axial compressive force is increased, the onset of flexural cracking is delayed.

Which of the following best describes a smeared-crack model?

A rectangular beam with cross section b = 16 in., h = 22 in., and d = 19.5 in. supports a total factored uniform load of 1.60 kips/ft, including its own dead load. The beam is simply supported with a 18-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 4,200 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 = 130.3 kip-ft, and the strength of the remaining two bars is φMn = 53.5 kip-ft. Determine the distance from the support to the theoretical cutoff point (i.e. disregard ACI 318-14 Section 9.7.3.3).

For a beam with stirrup hooks, the free end of the bar must extend at least _____ from the hook. Assume b = 14 in., d = 28 in., and that there are four No. 9 longitudinal tension bars and No. 4 stirrups at 7 in. o.c. The stirrup hooks are 135°.

Researchers studying reinforced concrete have considered a mechanical explanation of Vc to be the Holy Grail.

If φVc = 66 kip and Vu = 26 kip, are stirrups required?

The use of compression reinforcement permits the use of more tension reinforcement to increase the strength of a given beam section while keeping the section tension-controlled.

Determine the transverse reinforcement index, Ktr, for a rectangular beam with b = 17 in. and d = 24 in., three uncoated No. 8 Grade 60 tension-reinforcement bars placed in the bottom of the beam, and No. 3 Grade 40 stirrups located every 6 in. along the span. Assume 4,000-psi normal-weight concrete and a clear cover of 1.75 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 = 4,000 psi, fyt = 40,000 psi, d = 23 in., w = 13.5 in., and t = 6 in. There are five No. 7 longitudinal tension bars and No. 5 stirrups at 6 in. o.c.