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

A simply supported beam with dimensions of b = 16 in., h = 22 in., d = 19.5 in., and L = 25 ft supports a uniform service (unfactored) dead load of 1.766667 kips/ft including its own self weight plus a uniform service (unfactored) live load of 1.0 kips/ft. The beam is reinforced with four No. 5 Grade 60 bars. The concrete strength is 7,000 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the effective moment of inertia, Ie.The cracked moment Mcr = 67.49 kip-ft, and the maximum applied bending moment due to the combined service loads (dead plus live) Ma = 216.1 kip-ft. The neutral axis location of the cracked beam (measured from the top of the beam) is 3.8417 in.

Deflections greater than about L/250 of the span are generally visible for simple or continuous beams.

A(n) _______ limit state signifies a threat of collapse; a(n) _______ limit state does not.

Determine the required splice length for the galvanized longitudinal bars in the following tied column made of normal-weight concrete. Assume that some of the longitudinal bars are in tension and that the connection should be designed as a Class B contact lap splice. Use ACI 318-14 Table 25.4.2.2 to calculate the development length, and assume that the ties satisfy the Code minimum.Column width, b = 22 in.Column thickness, h = 12 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 12Size of longitudinal bars = No. 9Size of ties = No. 4Concrete strength = 5,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Fatigue failures of reinforced concrete structures are rare.