Assuming Vs exceeds 4sqrt(f’c)bwd, the maximum spacing for vertical stirrups in the following beam is _____. Let b1 = 20 in., b2 = 11 in., d = 45 in., h1 = 6 in., h2 = 35 in., h3 = 9 in., and t = 7 in. There are sixNo. 8 longitudinal tension bars and No. 3 stirrups at 11 in. o.c.

Determine the lightweight modification factor, λ, for a rectangular beam with b = 17 in. and d = 22 in., three galvanized No. 6 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 10 in. along the span. Assume 7,000-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, b1 = 34 in., b2 = 12 in., d1 = 8 in., d2 = 19 in., and that there are three No. 6 longitudinal tension bars and No. 4 stirrups at 9 in. o.c. The stirrup hooks are 90°.

Determine the bar-spacing factor, cb, for a simply supported rectangular beam with b = 24 in. and No. 4 stirrups. This beam has three No. 8 bars as longitudinal reinforcement. The clear cover is 1.5 in.

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 16 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 60 stirrups located every 6 in. along the span. Assume 7,000-psi lightweight concrete and a clear cover of 2 in.

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 16 in. and d = 23 in., four uncoated No. 7 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 4 Grade 60 stirrups located every 12 in. along the span. Assume 6,000-psi normal-weight concrete and a clear cover of 1.5 in.

Compute φVn for the cross section shown. Assume f’c = 7,500 psi, fyt = 40,000 psi, b1 = 29 in., b2 = 12 in., d1 = 6 in., d2 = 17 in., and that there are three No. 7 longitudinal tension bars and No. 4 stirrups at 10 in. o.c.

A rectangular beam has a cross section of b = 18 in., h = 24 in., and d = 21.5 in. It is reinforced with five No. 5 Grade 60 bars. The concrete strength is 8,200 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. Determine the strength φMn for this beam.

If φVc = 51 kip and Vu = 40 kip, are stirrups required?

A 122-mm-long beam supports a load of P = 27 N at midspan. The cross section is rectangular with width b = 29 mm and height h = 40 mm. Determine the magnitude of the horizontal shear stress at the centroid of the cross section.