ACI Code Section 9.7.3.3 arbitrarily requires longitudinal tension bars be extended a minimum distance equal to the greater of d or 12 bar diameters past the theoretical cutoff point for flexure.

Determine the epoxy modification factor, ψe, for a rectangular beam with b = 18 in. and d = 22 in., three epoxy-coated No. 9 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 8,000-psi normal-weight concrete and a clear cover of 1.75 in.

The primary purpose for the continuity and structural integrity reinforcement requirements is to tie the structural elements together and prevent localized damage from spreading.

Determine the size modification factor, ψs, for a rectangular beam with b = 16 in. and d = 21 in., three galvanized No. 8 Grade 60 tension-reinforcement bars placed in the bottom of the beam, and No. 4 Grade 60 stirrups located every 6 in. along the span. Assume 8,000-psi normal-weight concrete and a clear cover of 1.75 in.

In welded-wire reinforcement, deformed-wire reinforcement derives anchorage from bond stresses along the _______ wires and from mechanical anchorage from the _______ wires.

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 = 18 in. and d = 24 in., five galvanized No. 9 Grade 60 bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 6 in. along the span. Assume 5,000-psi lightweight concrete and a clear cover of 1.5 in.

A rectangular beam with cross section b = 16 in., h = 20 in., and d = 17.5 in. supports a total factored uniform load of 1.00 kips/ft, including its own dead load. The beam is simply supported with a 21-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 6,300 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 four bars is φMn = 95.23 kip-ft, and the strength of the remaining two bars is φMn = 48.22 kip-ft. If the distance from the support to the theoretical cutoff point is 6.784 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).

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.

Hooks can be attached to one or both ends of a bar by internal threads on the hook mating to the bar, welding or forging onto the bar, or by a separate nut used to secure the hook onto the bar.

The stress in reinforcing steel is _______ at cracks, while the concrete stress is _______ at cracks.