A simply-supported beam has a 5 kip/ft uniformly-distributed load over the entire 12-ft span. What is the magnitude of the shear force at midspan?
In a compression lap splice, a portion of the force transfer…
In a compression lap splice, a portion of the force transfer is through the bearing of the end of the bar on the concrete. This transfer and the fact that no transverse tension cracks exist in the splice length allow compression lap splices to be much _______ than tension lap splices. Frequently, a _______ lap splice will fail by spalling of the concrete under the ends of the bars.
A rectangular beam has a cross section of b = 16 in., h = 22…
A rectangular beam has a cross section of b = 16 in., h = 22 in., and d = 19.5 in. It is reinforced with two No. 7 Grade 60 bars. The concrete strength is 9,100 psi (normal weight). The beam has Grade 60 No. 3 stirrups satisfying ACI 318-14 Sections 9.7.6.2.2 and 9.6.3.3. Determine the strength φMn for this beam.
When the steel ratio, ρw, is small, flexural cracks extend _…
When the steel ratio, ρw, is small, flexural cracks extend _______ into the beam and open _______ than would be the case with large values of ρw.
Determine the bar-spacing factor, cb, for a simply supported…
Determine the bar-spacing factor, cb, for a simply supported rectangular beam with b = 22 in. and No. 3 stirrups. This beam has three No. 7 bars as longitudinal reinforcement. The clear cover is 1.6 in.
The largest and smallest normal stresses acting on an elemen…
The largest and smallest normal stresses acting on an element are referred to as _______.
A rectangular beam with cross section b = 16 in., h = 20 in….
A rectangular beam with cross section b = 16 in., h = 20 in., and d = 17.5 in. supports a total factored uniform load of 3.60 kips/ft, including its own dead load. The beam is simply supported with a 18-ft span. It is reinforced with five No. 8 Grade 60 bars, three of which are cutoff between midspan and the support and two of which extend 10 in. past the centers of the supports. The concrete strength is 6,300 psi (normal weight). The beam has Grade 60 No. 3 stirrups satisfying ACI 318-14 Sections 9.7.6.2.2 and 9.6.3.3. The strength of the five bars is φMn = 286.5 kip-ft, and the strength of the remaining two bars is φMn = 120.5 kip-ft. Determine the distance from the support to the theoretical cutoff point (i.e. disregard ACI 318-14 Section 9.7.3.3).
A rectangular beam with cross section b = 16 in., h = 28 in….
A rectangular beam with cross section b = 16 in., h = 28 in., and d = 25.5 in. supports a total factored uniform load of 3.50 kips/ft, including its own dead load. The beam is simply supported with a 23-ft span. It is reinforced with four No. 8 Grade 60 bars, two of which are cutoff between midspan and the support and two of which extend 10 in. past the centers of the supports. The concrete strength is 3,600 psi (normal weight). The beam has Grade 60 No. 3 stirrups satisfying ACI 318-14 Sections 9.7.6.2.2 and 9.6.3.3. The strength of the four bars is φMn = 335.1 kip-ft, and the strength of the remaining two bars is φMn = 174.4 kip-ft. If the distance from the support to the theoretical cutoff point is 5.791 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).
A rectangular beam with cross section b = 14 in., h = 22 in….
A rectangular beam with cross section b = 14 in., h = 22 in., and d = 19.5 in. supports a total factored uniform load of 1.10 kips/ft, including its own dead load. The beam is simply supported with a 22-ft span. It is reinforced with four No. 5 Grade 60 bars, two of which are cutoff between midspan and the support and two of which extend 10 in. past the centers of the supports. The concrete strength is 6,600 psi (normal weight). The beam has Grade 60 No. 3 stirrups satisfying ACI 318-14 Sections 9.7.6.2.2 and 9.6.3.3. The strength of the four bars is φMn = 106.2 kip-ft, and the strength of the remaining two bars is φMn = 53.74 kip-ft. If the distance from the support to the theoretical cutoff point is 6.174 ft, determine the distance from the support to the actual cutoff point (i.e. use ACI 318-14 Section 9.7.3.3).
Use ACI 318-14 Table 25.4.2.2 to determine the development l…
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 = 22 in., three uncoated No. 7 Grade 60 bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 10 in. along the span. Assume 6,000-psi lightweight concrete and a clear cover of 2 in.