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Structural Concrete - Hassoun

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978 Chapter 24 Design and Analysis Flowcharts<br />

Given: b w , d, f′ c , f y , bars<br />

Required: Development length<br />

f′ c ≤ 100 psi<br />

Compression bars<br />

Tension bars<br />

1 dc = (0.02d b f y )/λ f′ c<br />

1 dc = 0.0003d b f y<br />

(for no. 7 and large bars)<br />

1 d1 /d b = ψ t ψ e f y /20λ f′ c<br />

(for no. 6 and small bars)<br />

1 d1 /d b = ψ t ψ e f v /25λ f′ c<br />

1 d = 1 dc* (R s or R s1 , if applicable)<br />

1 d ≥ 8 in.<br />

R s = A s (required)/A s (provided)<br />

R s1 = 0.75 for spiral columns<br />

No<br />

Is<br />

c ≥ d b<br />

s ≥ d b<br />

or s > 2d b<br />

(1)<br />

Yes<br />

1 d = 1.51 d1 ≥ 12 in. 1 d = 1 d1 ≥ 12 in.<br />

Flowchart 24.8<br />

Calculation of development length.<br />

1. c = clear cover<br />

s = clear spacing

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