I have a 10" slab with Gr. 60 #6 at 18" OC each way T&B (steel density provided= .0024 each face) and I'm getting a design status error for ACI 318-14 section 8.6.1.1 (minimum steel). When I use the section audit, it appears as though the steel is accounted for and developed and has sufficient density (.0022). I'm confused at what is prompting this error - any help? Thank you,.
At 18" spacing some strips may have one fewer bars than you expect based on average steel area and the program uses the literal number of bars. So in this case. 1.76 in^2 / (10" * 79.75") = 0.0022, but that still ought to work. Can you send the file?
Roof_partial.cpt
In the Audit I see:
Two-way slab in critical span region - checking 2 * h spacing limit (per 8.7.2.2).Checking 8.6.1.1Ac 797.5 in²Reinforcing Ratio (using all reinforcement) 0.002207Modified Reinforcing Ratio (fy > 60 ksi) 0.002207Maximum allowed bar spacing 18 inchesMaximum actual bar spacing 19.94 inches
What's happening is illustrated below:
You can ignore it since your spacing is literally 18" OC (or turn off code min design rule).
Answer Verified By: Stephen Figueira
Thank you