IRS Bridge

The density is assumed to be 2300 kg/m³.

The design strength is given in 15.4.2.1(b) by

$$f_{cd}=0.6 f_c /\gamma \\$$

The tensile strength is given in 16.4.4.3 as

$$f_{ct}=0.37 \sqrt{f_c} \\$$

The elastic modulus is tabulated in 5.2.2.1

$f_c$ (MPa)	$E$ (GPa)
20	25.0
25	26.0
32	28.0
40	31.0
50	34.0
60	36.0

The strains are defined as

	$\varepsilon_{cu}$	$\varepsilon_{ax}$	$\varepsilon_{plas}$	$\varepsilon_{max}$	$\varepsilon_{peak}$
Parabola-rectangle	0.0035	$\varepsilon_{cu}$	$\varepsilon_{RP}$
Rectangle
Bilinear
Linear				0.0035	$\varepsilon_{max}$
Non-linear
Popovics
EC2 Confined
AISC filled tube
Explicit	0.0035	$\varepsilon_{cu}$		0.0035

$$\varepsilon_{RP}=2.4 \times 10^{-4} \sqrt{\frac{f_c}{\gamma}} \\$$

See also the Theory section on Concrete material models.