Cracks in a member increase the member’s moment of inertia, thereby decreasing the member’s stiffness.

A rectangular beam has a cross section of b = 16 in., h = 26 in., and d = 23.5 in. It is reinforced with four No. 8 Grade 60 bars. The concrete strength is 7,000 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the cracking moment, Mcr.

Compute φVn for the cross section shown. Assume f’c = 7,500 psi, fyt = 60,000 psi, b1 = 29 in., b2 = 13 in., d1 = 7 in., d2 = 14 in., and that there are three No. 9 longitudinal tension bars and No. 3 stirrups at 6 in. o.c.

In seismic regions, ties are generally spaced approximately one column width apart.

For the first few years, the time required for a corrosion cell to be established in the reinforcement is not a function of concrete crack width.

Because designers have little control over the arrangement of the bars in a circular column, the interaction diagram should be computed for the most favorable bar orientation.

The strength reduction factor for shear is _____.

Cracks in a member increase the member’s moment of inertia, thereby decreasing the member’s stiffness.

When a section cracks, its moment of inertia decreases, leading to a decrease in the stiffness of the beam.

Use the interaction diagrams found in Appendix A of the textbook to determine whether the following rectangular tied column with bars in 2 faces can safely support a load of Pu = 720 kip and Mu = 360.0 kip-ft.b = 18 in.h = 20 in.fc’ = 4 ksify = 60 ksiγ = 0.6ρg = 0.05