AASHTO Guide Spec, SDC A

[Phred404]

Looking at 8.8.9 of the Guide Spec, #5 bars are required for Lateral reinforcement for longitudinal bars #10 or larger. Given that the Guide Spec has requirements for the hoop spacing, why would they require a larger lateral reinforcement bars? We can meet the spacing requirement with a tighter spacing of #4 bars. This is for SDC A with SD1>1.0

 

[1ManWolfpack]

If your SD1 > 1.0, how are you in SDC A?

 

[Phred404]

Right. That pesky decimal point. SD1=0.116. This is greater than 0.10 and our Site Class is D, so SDC is A(high)

 

[1ManWolfpack]

Had a feeling you may have misplaced that decimal haha. I'm guessing it has something to do with what they mention in the Commentary for that section; in addition to providing shear strength, the hoops also serve to brace the longitudinal column steel.