trying to determine grade of old steel in bridge

[black79ta]

hello all,

I am designing a jacking system to exchange out bridge bearings for an IDOT (Illinois DOT) bridge built in 1961. While looking at the drawings of the existing structure, the steel called out for is:

A.S. steel and W.S. steel.

Does anyone know what the yield and ultimate strengths are for these 2 types of steel?


thanks in advance.

 

[hokie66]

It must mean something other than the grade of steel. By any chance, is the "W.S." weathering steel?

 

[black79ta]

I was wondering the same thing. I recall a type of steel called A7, but A.S. and W.S. has me stumped. I have a book about old sections and steel grades but the "youngest" steel mentioned is 1953. Thanks for your input though.

 

[bridgebuster]

Are you dealing with shapes or built up sections? A7 was common for shapes until the the early 60's; Fy = 33ksi.

AS could mean alloy steel - silicon or nickle. I would agree that WS would mean weathering steel - easy to verify if you go to the site or have someone send you a photo. These steels would be more common in a built up member. An alloy steel could have a yield of anywhere from 45 (silicone steel) to 55 ksi (nickel steel). I don't know if shapes were available in alloy or weathering steel back then.

AASHTO Manual for Condition Evaluation of Bridges or AASHTO Bridge Evaluation Manual, even the old Maintenance Manual provide tables for determining steel strength.

 

[Qshake]

Bridgebuster has a good source, the MBE. This manual has charts for materials used in bridges by era or year. Since this was built in the early 60s I would think you'd have an easy time of finding the info.

Since you mention IDOT, you should call your contact and ask them if they have shop drawings for the bridge and thus information on the material strength.

if all else fails you can have a coupon cut and tested.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[dik]

Are there any mill rolling marks on the sections?

Dik

 

[bridgebuster]

If you can't get the shop drawings and if you're dealing with shapes another source would be AISC Steel Construction Manual, 5th Edition.

I have the 6th Ed. 1963, which indicates certain shapes were being produced under A242, A440, and A441, perhaps some of these were being rolled in the late 50's/early 60's. These grades would be considered alloy steel.

 

[DWHA]

Check out the "Bridge Rating and Posting IDOT Burea of Local Roads and Streets" I have a single sheet from this manual (mine is dated 12/07/90) and it states:

Date Built Fy Inventory Posting Operating & Posting
1930 - 61 33 18.15 21.45 24.75
After 61 36 20 23.5 27

So if I had to do this jacking and replacement of bearings, I would use the 33ksi.

 

[black79ta]

Thanks guys for your help. A friend of mine had a copy of the MBE. Using that I determined that the steel used in that time frame is 33ksi steel. I still don't know what AS and WS stand for, but I have used the 33ksi for my design.