Good morning!
I was wondering if Concept applies the following section calculations when designing slab systems:
-ACI 318-11: 13.5.3 and 11.11.7
-ACI 318-14: 8.4.2.3 and 8.4.4.2
-ACI 318-19: 8.4.2.2 and 8.4.4.2
Each of these provisions deal with the moment transfer at slab-column connections, where a portion of the unbalanced moment is resisted in shear and the rest resisted in flexural reinforcement.
The unbalanced moment resisted in shear is accounted for in the punching shear design.
Currently, the unbalanced moment transferred through flexure is not accounted for in the design. However, the next version of RAM Concept (v8.3.0), which will be released soon, will include an option to design flexural reinforcement for that effect if ACI 318-14 or ACI 318-19 is selected for the design code. More on that new feature can be found in the release notes, which are posted here.
Answer Verified By: Eric Feuge-Miller
Karl,
When in the "Flexural Sections" tab, are the top & bottom bar selections using that selected bar's respective fy for the calculation of the flexural steel required per 8.4.2.3?
I'm also assuming that as long as the At (flexural steel required per 8.4.2.3) is less than the overall demand required As that the program will spit out that overall As for detailing purposes. And that's it.It's still up to the designer/engineer to ensure that the At is detailed to be placed within the effective slab width (1.5h from both sides of column face) and that the remaining steel is within the rest of the column strip. That also brings up another question that if that leftover steel isn't enough to meet the max spacing requirement, say the 18", the designer/engineer needs to ensure extra steel is provided to meet that max spacing.
Yes, that bar's respective Fy is used in the calculations.
The reinforcement required for the 8.4.2.3 check will be detailed on the Reinforcement Layer with other reinforcement required for other checks. RAM Concept uses a flexural section that matches the effective slab width defined by ACI 318. The flexural section reinforcement is detailed across this width by the program, there is no need for the designer/engineer to do this outside the program. If the total reinforcement required for a column strip exceeds the 8.4.2.3 requirement, you will find one set of bars bundled over the column with the defined effective slab width and the remainder detailed over the other portions of the column strip. Spacing checks would be enforced for each groups of bars.
That's awesome. Made my life that much easier.
Thanks, Karl.