Life-Cycle Management Strategy on Steel Girders in Bridges

Table 5

Statistical parameters of random variables for the illustrative example.

Parameters	Materials	Variables	Mean (𝜇)	C.O.V.(1) (𝜎/𝜇)	Distribution	Sources
Corrosion deterioration rate	Carbon steel	A	70.6 𝜇m	0.66	LN(2)	[5, 6]
		B	0.789	0.49
		𝜌𝐴𝐵	−0.31	—	—
	Weathering steel	A	40.2 𝜇m	0.22	LN
		B	0.557	0.10
		𝜌𝐴𝐵	−0.45	—	—
Corrosion Initiation	—	𝑇CI	15 yr	0.30	LN	[7]
Repaint duration	—	T REP	20 yr	0.25
Initial crack dimension	Structural steel	𝑎0	0.762 mm	0.5	LN	[14]
Crack growth constant		C	1.26×10^−13	0.63
Crack growth exponent		m	3	—	Constant	[15]
Critical crack dimension		𝑎𝑐	0.0254 m
Fracture toughness		𝐾IC	43.97 MPa m^0.5	0.19	TN(3)	[10]
Compressive strength	Concrete	𝑓𝑐	21 MPa(4)	0.19	LN	[9]
Yield stress	Steel	𝐹𝑦	248 MPa	0.10
Modulus of elasticity	Concrete	𝐸𝑐	30,000 MPa	0.20	LN	[16]
	Steel	𝐸𝑠	210,000 MPa	0.06
Deck slab thickness	Concrete	𝑡𝑐	191 mm	0.20	N(4)	[14]

(1)C.O.V.: coefficient of variation.
(2)LN: lognormal distribution.
(3)TN: truncated normal distribution.
(4)N: normal distribution.