If the bond between concrete and steel in a beam disappears, the steel will not pull out of the concrete.

A rectangular beam with cross section b = 16 in., h = 28 in., and d = 25.5 in. supports a total factored uniform load of 2.80 kips/ft, including its own dead load. The beam is simply supported with a 22-ft span. It is reinforced with four No. 7 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 7,200 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 four bars is φMn = 267.5 kip-ft, and the strength of the remaining two bars is φMn = 135.7 kip-ft. If the distance from the support to the theoretical cutoff point is 6.094 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).

Which of the following should NOT be used to determine the location of bar cutoff points?

In a lapped splice, the force in one bar is transferred to the concrete, which transfers it to the adjacent bar.

When a deformed bar is loaded for the first time, the adhesion and friction are quickly lost, leaving the bond to be transferred by _______.

A rectangular beam has a cross section of b = 16 in., h = 26 in., and d = 23.5 in. It is reinforced with five No. 7 Grade 60 bars. The concrete strength is 5,200 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.

Determine the lightweight modification factor, λ, for a rectangular beam with b = 17 in. and d = 24 in., three 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 7,000-psi lightweight concrete and a clear cover of 2 in.

A simply supported beam with dimensions of b = 14 in., h = 26 in., d = 23.5 in., and L = 21 ft supports a uniform service (unfactored) dead load of 1.579167 kips/ft including its own self weight plus a uniform service (unfactored) live load of 0.8 kips/ft. The beam is reinforced with five No. 8 Grade 60 bars. The concrete strength is 2,500 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Using the effective moment of inertia, determine the immediate mid-span deflection of the beam due to the combined service loads (dead plus live).The effective moment of inertia Ie = 12,311 in.4.

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 17 in. and d = 21 in., three galvanized No. 9 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 40 stirrups located every 8 in. along the span. Assume 6,000-psi lightweight concrete and a clear cover of 2 in.

In deformed reinforcing bars, adhesion and lateral friction are significant sources of bond strength.