Time-Dependent Deflection is calculated automatically.
As' = area of the compression reinforcement, in2
b = width of compression face of member, in.
d = distance from extreme compression fiber to centroid of logitudinal tension reinforcement, in.
ρ' = ratio of As' to bd
ξ = time-dependent favtor for sustained load
λΔ = multiplier used for additional deflection due to long-term effects
According to ACI 126.96.36.199.1. additional time-dependent deflection resulting from creep and shrinkage of flexural members can be calculated as the product of immediate deflection caused by sustained load and the factor λΔ.
ρ' is the ratio of the As' ,area of the compression reinforcement, to bd
Time-dependent factor ξ is calculated in accordance with ACI Table 188.8.131.52.3