A concrete floor system with a ratio of the longer to the shorter span length that is less than or equal to 2 is usually considered a one-way system.

At a point subjected to plane stress, the stresses are σx = –40 MPa, σy = –100 MPa, and τxy = –50 MPa. Determine the angle θp corresponding to the orientation of the principal planes at the point.

A beam has dimensions of b = 20 in., h = 10 in., and d = 7.5 in. and is reinforced with 4 No. 7 bars. The concrete strength is 4,700 psi, and the yield strength of the reinforcement is 60,000 psi. If the depth of the neutral axis is c = 2.211 in., does the reinforcement yield?

A continuous beam’s flexural reinforcement must extend at least _____ from the point where it is no longer needed to resist tension. Assume f’c = 4,000 psi, fyt = 40,000 psi, d = 28 in., w = 18.5 in., and t = 6 in. There are five No. 6 longitudinal tension bars and No. 4 stirrups at 11 in. o.c.

A beam has dimensions of b = 18 in., h = 30 in., and d = 27.5 in. and is reinforced with 5 No. 7 bars. The concrete strength is 7,300 psi, and the yield strength of the reinforcement is 60,000 psi. If the depth to the neutral surface is c = 2.352706 in., determine the strain in the reinforcement.

When faced with severe architectural restrictions on the dimensions of a beam, a designer may be forced to use a singly reinforced section.

Bars of longitudinal reinforcement often do not have to extend the full length of a beam.

A beam has dimensions of b = 18 in., h = 28 in., and d = 25.5 in. and is reinforced with 2 No. 7 bars. The concrete strength is 10,000 psi, and the yield strength of the reinforcement is 60,000 psi. Determine the strength Mn for this beam.

Bars of longitudinal reinforcement often do not have to extend the full length of a beam.

Compute φVn for the cross section shown. Assume f’c = 7,500 psi, fyt = 40,000 psi, b = 12 in., d = 25 in., and that there are four No. 8 longitudinal tension bars and No. 3 stirrups at 9 in. o.c.