## Long Term Deflection for Concrete:

Long term deformation (or deflection), Δ, is found by multiplying an amplification factor (λ) by the initial deflection (Δ_{i}).

The long term deflection is found by using the following equation:**Δ = λ Δ _{i}**

*where:*

Δ

λ = amplification factor = i\over {1+50ρ'}

i = 1.0 (for 3 months), 1.2 (for 6 months), 1.4 (for 1 year), 2.0 (for 5+ years)

p' = the compression steel ratio = A'_s\over bd

b = the width of the concrete beam

d = the depth of the concrete beam (note: that this is not the same as the height of the beam)

_{i}= the initial deflection? of the concrete beamλ = amplification factor = i\over {1+50ρ'}

i = 1.0 (for 3 months), 1.2 (for 6 months), 1.4 (for 1 year), 2.0 (for 5+ years)

p' = the compression steel ratio = A'_s\over bd

b = the width of the concrete beam

d = the depth of the concrete beam (note: that this is not the same as the height of the beam)