Section 4152.  Structural Steel

                                                        

4152.01     general requirements.

Meet the following requirements unless alloy steel is specified in the contract documents. For alloy steel, meet the requirements specified in the contract documents for each project on which such steel is specified.

 

4152.02     STRUCTURAL STEEL.

 

A.    Use the type and quality designated in the contract documents. When not specifically designated, use structural carbon steel meeting the requirements of ASTM A 709 Grade 36. Miscellaneous items not commonly rolled from steel meeting these requirements may be furnished in other grades of steel with the Engineer’s approval.

 

B.    Unless noted otherwise, apply Charpy V-notch toughness requirements of Table 4152.02-1 to the following members. Ensure members are sampled and tested according to AASHTO T 243 (ASTM A 673).

 

1.     Flange and web plates of welded plate girders.

 

2.     Rolled section main beams, stringers, and welded cover plates.

 

3.     Flange and web splice plates.

 

4.     Rolled or welded floor beams, abutment diaphragms, and cross frames carrying direct live loads, and all parts, except shear connectors, welded to each of these members.

 

5.     Lateral bracings and connecting gusset plates in horizontally curved bridges.

 

C.    For members designated in the contract documents as Fracture Critical, apply Charpy V-notch toughness requirements of Table 4152.02-2. Ensure members are sampled and tested according to AASHTO T 243 (ASTM A 673).

 

D.    The contract documents may also designate other members to which toughness requirements apply.

 

Table 4152.02-1: Non-Fracture Critical Impact Test Requirements

Grade

Thickness (in.)

Minimum Average Energy,
ft.lbf. at °F

36T(a)

to 4, incl.

15 at 40

50T(a, b), 50WT(a, b)

 

to 2, incl.

over 2 to 4, incl.

15 at 40

20 at 40

HPS 70WT (c)(,d)

to 4, incl.

25 at -10

HPS 100WT(c)

to 2 1/2, incl.

over 2 1/2 to 4, incl.

25 at -30

35 at -30

(a)   CVN-impact testing shall be at "H" frequency in accordance with ASTM A 673.

(b)   If the yield point of the structural product exceeds 65 ksi, the testing temperature for the minimum average energy required by 15°F for each increment or fraction of 10 ksi above 65 ksi. The yield point is the value given on the certified "Mill Test Report".

(c)   CVN-impact testing shall be at "P" frequency in accordance with ASTM A 673.

(d)    If the yield strength of the structural product exceeds 85 ksi, the testing temperature for the minimum average energy required shall be reduced by 15°F for each increment or fraction of 10 ksi above 85 ksi. The yield strength is the value given on the certified “Mill Test report.

 

Table 4152.02-2: Fracture Critical Impact Test Requirements

Grade

Thickness (in.)

Minimum Test Value Energy,
ft.lbf.

Minimum Average Energy,
ft.lbf. at °F

36F(a)

to 4, incl.

20

25 at 40

50F(a, b), 50WF(a, b)

 

to 2, incl.

over 2 to 4, incl.

20

24

25 at 40

30 at 40

HPS 50WF(a, b)

to 4, incl.

24

30 at 10

HPS 70WF (a, c)

to 4, incl.

28

35 at -10

HPS 100WF(a)

to 2 1/2, incl.

over 2 1/2 to 4, incl.

28

Not Applicable

35 at -30

Not Permitted

(a)   CVN-impact testing shall be at "P" frequency in accordance with ASTM A 673 except for plates, for which the sampling shall be as follows:

(1)    As-rolled (including control-rolled and TMCP) plates shall be sampled at each end of each plate-as-rolled.

(2)    Normalized plates shall be sampled at one end of each plate, as heat treated.

(3)    Quenched and tempered plates shall be sampled at each end of each plate, as heat treated.

(b)   If the yield point of the structural product exceeds 65 ksi, the testing temperature for the minimum average energy and minimum test value energy required shall be reduced by 15°F for each increment or fraction of 10 ksi above 65 ksi. The yield point is the value given on the certified "Mill Test Report".

(c)    If the yield strength of the structural product exceeds 85 ksi, the testing temperature for the minimum average energy and minimum test value energy required shall be reduced by 15°F for each increment or fraction of 10 ksi above 85 ksi. The yield strength is the value given on the certified "Mill Test Report".

 

4152.03 Shear Connector Studs

 

A.   Comply with ASTM A 108 for steel bars, carbon cold-finished, standard quality, Grades 1010 through 1020 inclusive either semi-killed or killed deoxidation. Inspection and acceptance of shear connector studs will be according to Materials I.M. 453.10.

 

B.    Provide an arc shield (ferrule) of heat-resistant ceramic or other suitable material when approved by the Engineer. Ferrules shall be kept dry and protected from moisture or oven dried at 250°F for 2 hours.