Stress and strain of uncracked sections - Concrete Structures: Stresses and Deformations - page 56

Table 2.5 Properties of the composite age-adjusted transformed section used in
calculation of the changes of stress and strain between t 2 = 60 days
and t 3 = ∞ .

Properties of area Properties of transformed

area

A B I AE / E ref BE / E ref IE / E ref

(m 2 ) (m 3 ) (m 4 ) (m 2 ) ( 3 ) ( 4 )

Concrete of
deck slab

0.495

− 0.4307

0.3763 0.3017

− 0.2625

0.2294

Non-
prestressed
steel in deck
slab 5000 × 10 − 6

− 4350 × 10 − 6

3785 × 10 − 6 0.0761

− 0.0662

0.05763

Concrete in
beam 0.5090 0.0 0.1090 0.5090 0.0 0.1090

Non-
prestressed
steel in beam 3000 × 10 − 6

− 210 × 10 − 6

1282 × 10 − 6 0.0457

− 0.0032

0.0195

Prestressed steel 3160 × 10 − 6 1675 × 10 − 6 887.6 × 10 − 6 0.0481 0.0255 0.0135

Properties of the age-adjusted 0.9806

− 0.3064

0.4290

¯ ¯ ¯ transformed section

Figure 2.12 Changes in stress and strain in the composite section of Example 2.5
due to creep, shrinkage and relaxation occurring between casting of the
deck slab, t 2 = 60 days and t 3 = ∞.

3160 × 10 −6 ( 70×10 6 )

3160 × 10 −6 × 0.53 (

∆ N − − 0.221 N

relaxation = = 10 6

70 × 10 6 ) ∆ M − − 0.117N-m