Per ACI 318 standards (Section 25.4.2.1 in 2014 edition) and the homework, when calculating the development length of deformed bars, what is the minimum value of ld?

A rectangular beam has a cross section of b = 18 in., h = 22 in., and d = 19.5 in. It is reinforced with four No. 8 Grade 60 bars. The concrete strength is 8,800 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the cracking moment, Mcr.

Which is generally shorter?

Determine the casting-position modification factor, ψt, for a rectangular beam with b = 16 in. and d = 20 in., five galvanized No. 7 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 60 stirrups located every 12 in. along the span. Assume 4,000-psi normal-weight concrete and a clear cover of 1.5 in.

Heads can be attached to one or both ends of a bar by internal threads on the head mating to the bar, welding or forging onto the bar, or by a separate nut used to secure the head onto the bar.

A rectangular beam has a cross section of b = 18 in., h = 24 in., and d = 21.5 in. It is reinforced with five No. 5 Grade 60 bars. The concrete strength is 6,400 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.

A simply supported beam with dimensions of b = 14 in., h = 30 in., d = 27.5 in., and L = 24 ft supports a uniform service (unfactored) dead load of 1.5375 kips/ft including its own self weight plus a uniform service (unfactored) live load of 1.2 kips/ft. The beam is reinforced with two No. 5 Grade 60 bars. The concrete strength is 7,600 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Using the effective moment of inertia, determine the immediate mid-span deflection of the beam due to the combined service loads (dead plus live).The effective moment of inertia Ie = 8,000 in.4.

Failure of a hooked anchorage rarely involves crushing of the concrete inside the hook.

A simply supported beam with dimensions of b = 18 in., h = 30 in., d = 27.5 in., and L = 22 ft supports a uniform service (unfactored) dead load of 2.2625 kips/ft including its own self weight plus a uniform service (unfactored) live load of 1.2 kips/ft. The beam is reinforced with five No. 8 Grade 60 bars. The concrete strength is 9,700 psi (normal weight). The beam has Grade 60 No. 3 stirrups. Determine the effective moment of inertia, Ie.The cracked moment Mcr = 166.2 kip-ft, and the maximum applied bending moment due to the combined service loads (dead plus live) Ma = 209.5 kip-ft. The neutral axis location of the cracked beam (measured from the top of the beam) is 6.8434 in.

Map cracking can be controlled by limiting the heat rise due to the heat of hydration and the rate of cooling, or both; by placing the wall in short lengths; or by reinforcement considerably in excess of normal shrinkage reinforcement.