Fabian Gonzales's Activities

RAM Concept - Net Axial Forces not zero in RC Slab

Fabian Gonzales — Thu, 04 Aug 2022 17:56:01 GMT

Hi,

I have a template of a 40ftx20ft RC slab in Concept that I sometimes use to make quick studies or to verify my hand calculations. While looking at the net axial stresses I noticed that they are not equal to zero; in fact ,the axial forces are in compression everywhere in my slab. How is this possible? Net axial compression in my slab will result in reduced reinforcement demand, similar to columns, which is unconservative in slabs. I would expect to see net axial forces only in PT slab or in RC slab with steps or T-beams, but not in a RC flat slab.

Shear in PT beams when Design column strip for Column + Middle strip resultants is checked

Fabian Gonzales — Wed, 16 Mar 2022 20:03:16 GMT

Hi there,

I'm designing a parking PT slab with PT beams in a corner panel where we have higher loads. I noticed that the amount of shear reinforcement in the beams running parallel to the distributed tendon (longitude direction) increases exponentially when I have the "Design column strip for Column + Middle strip resultants" option checked. On the other hand, the amount of shear reinforcement in the beams running in the latitude direction changes very little whether we have the option checked or not.

I can't figure out why this happens, and would also like to know if I should have the "Design column strip for Column + Middle strip resultants" option checked. To my understanding, we have that options checked for beams in one-way slabs, but what about beams running in both directions in two-way slabs?

"Design column strip for Column + Middle strip resultants" checked.

"Design column strip for Column + Middle strip resultants" unchecked.

Latitude tendons

Longitude tendons

Thanks

Shear Capacity of PT Slab Zero

Fabian Gonzales — Mon, 20 Dec 2021 15:53:33 GMT

I have modeled a PT Slab and after running the calculations the Design Status shows shear failure at three strips right next to walls. When I looked at the shear capacity of those strips, I noticed that it has values of zero at mid span for the three strips. However, design strips on the other side of the wall do have shear capacities over zero (see image below). I also verified the shear cores and they seem coherent.

I'm hoping that you could help me out with this issue as I'm not able to find the mistake.

Change Column Elevation

Fabian Gonzales — Wed, 03 Nov 2021 19:27:15 GMT

Hi,

When drawing columns, RAM Concept draw them with an elevation of 0 by default; however, I'm trying to draw column in a slab with an elevation of -12 in. Right now my column go straight through my slab (see picture below). I haven't found any option to change column elevation as in slabs. How will it affect my model if I don't match column and slab elevation?

I'm working with RAM Concept 6.2 btw

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Wed, 03 Nov 2021 02:35:56 GMT

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