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If a designer wants to reduce the size and weight of a beam, he/she could use additional tension reinforcement and add compression reinforcement to keep the section tension-controlled.

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 = 23 in., w = 13.5 in., and t = 6 in. There are five No. 7 longitudinal tension bars and No. 5 stirrups at 6 in. o.c.

The use of compression reinforcement permits the use of more tension reinforcement to increase the strength of a given beam section while keeping the section tension-controlled.

At a point subjected to plane stress, the stresses are σx = 50 MPa, σy = –90 MPa, and τxy = 70 MPa. Determine the angle θp corresponding to the orientation of the principal planes at the point.

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

A beam has dimensions of b = 14 in., h = 28 in., d’ = 2.5 in., and d = 25.5 in. It is reinforced with 2 No. 5 bars on the compression side and 4 No. 8 bars on the tension side. The concrete strength is 2,500 psi, and the yield strength of the reinforcement is 60,000 psi. If the depth of the neutral axis is c = 6.268 in., determine the strain in the compression reinforcement, ε’s.

A classmate has suggested a beam design that has dimensions of b = 14 in., h = 28 in., and d = 25.5 in. and is reinforced with 4 No. 11 bars. Assuming a cover of 1.5 in. and a stirrup diameter of 0.5 in., does the reinforcement fit within a single row as suggested?

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

A beam has dimensions of b = 14 in., h = 28 in., d’ = 2.5 in., and d = 25.5 in. It is reinforced with 2 No. 5 bars on the compression side and 5 No. 8 bars on the tension side. The concrete strength is 4,000 psi, and the yield strength of the reinforcement is 60,000 psi. If the depth of the neutral axis is c = 5.216 in., determine the strain in the compression reinforcement, ε’s.

A beam has dimensions of b = 14 in., h = 26 in., d’ = 2.5 in., and d = 23.5 in. It is reinforced with 2 No. 5 bars on the compression side and 4 No. 8 bars on the tension side. The concrete strength is 2,500 psi, and the yield strength of the reinforcement is 60,000 psi. If the depth of the neutral axis is c = 6.268 in., determine the strain in the compression reinforcement, ε’s.