Blog

The stress in the reinforcement is minimum at a crack.

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 17 in. and d = 23 in., four galvanized No. 7 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 8,000-psi normal-weight concrete and a clear cover of 1.75 in.

Once a splitting crack develops, bond strength rapidly increases unless there is reinforcement designed to restrain opening of the crack.

Unlike exact bond stresses, the average bond stresses vary from point to point between cracks.

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 = 23 in., three galvanized No. 8 Grade 60 bars placed in the top of the beam, and No. 4 Grade 60 stirrups located every 6 in. along the span. Assume 5,000-psi normal-weight concrete and a clear cover of 2 in.

A simply-supported beam has a 4 kip/ft uniformly-distributed load over the entire 8-ft span. What is the magnitude of the shear force at midspan?

Hooks are used to provide additional anchorage when there is insufficient _______ available to develop a bar.

For economy, some of the bars can be terminated or cutoff where they are no longer needed.

Determine the lightweight modification factor, λ, for a rectangular beam with b = 17 in. and d = 22 in., five epoxy-coated No. 6 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 8,000-psi lightweight concrete and a clear cover of 1.5 in.

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.