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ACI 318-19 : Flexural Strength
TSC 2018 : TSC Flexural Strength
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Notation
As = area of nonprestressed longitudinal tension reinforcement, in2
α = depth of equivalent rectangular stress block, in.
bw = web width or diameter of circular section, in.
c = distance from extreme compression fiber to neutral axis, in.
Cc = concretecompressive force, lb
Cs = reinforcement tension force, lb
d = distance from extreme compression fiber to centroid of longitudinal tension reinforcement, in.
fc'= specified compressive strength of concrete, psi
fy = specified yield strength for nonprestressed reinforcement, psi
Mn = nominal flexural strength at section, in.-lb
ϕ = strength reduction factor
εt = net tensile strain in extreme layer of longitudinal tension reinforcement at nominal strength, excluding strains due to effective prestress, creep, shrinkage, and temperature
β1 = factor relating depth of equivalent rectangular compressive stress block to depth of neutral axis
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