Adrian Cabello's Activities

RAM Concept Minimum Code Reinforcement

Adrian Cabello — Mon, 25 Apr 2016 17:51:07 GMT

Dear RAM Concept team,

I am designing a slab to the Eurocode.

I have a uniform mat on top and bottom (User reinforcement) with an amount of reinforcement larger than the minimum required -chapter 9.3.1.1 (3)- and spacing smaller than the maximum allowed. When I audit the section I can verify that is considering CORRECTLY the minimum reinforcement from the code “As” and the maximum spacing “s” from the code. But it seems it doesn’t identify my mat and always needs additional reinforcement due to “Rule Set Design, Code Minimum Design”. Could you please test it on your machines and tell me if it is me doing something stupid or you have the same problem?

Thanks a lot, regards

Creep coefficient Eurocode

Adrian Cabello — Mon, 28 Nov 2016 17:24:15 GMT

Dear RAM team. I would like to ask you the following:

Is the creep coefficient that RAM is using for the Time history analysis the same as defined by the Eurocode 2? Thanks a lot, regards.

RAM Concept - earthworm symbol

Adrian Cabello — Tue, 13 Sep 2016 13:05:00 GMT

Dear RAM team. Hope you are all well.

I would like to ask you: what does this symbol mean? I don't find the meaning when I activate "Controlling criteria"

Thanks a lot! Regards

RAM Concept - Vibration - Error message

Adrian Cabello — Tue, 12 Apr 2016 11:06:18 GMT

Dear RAM team.

I am performing a vibration analysis and I want to use the “Final Instantaneous Load” Stiffness matrix. To that end, I run first the time history analysis but I still get the following error for any stiffness matrix different from the global one. What is the reason for that? Thanks

RAM Concept - Initial Service design

Adrian Cabello — Fri, 01 Apr 2016 10:36:54 GMT

Dear RAM Concept team.

I’ve got a question regarding “Initial Service load combination”. It is preset by default as:

The only information I find in the manual is concerning the factors to be used under this combination:

My doubt is: Which kind of verifications is RAM doing under this load combination? What is it doing when only “Initial Service design” in activated in the “Initial Service Combination”?

Thanks, best regards.

RAM reinforcement chapter 7.3 eurocode

Adrian Cabello — Wed, 02 Mar 2016 19:12:21 GMT

Dear RAM team.

I am doing a RC slab design following Eurocode 2. When RAM says that a reinforcement is required according to chapter 7.3, does it mean 7.3.2?

Because when I check my crack width for the given quasi-permanent moment and the reinforcement required for strength, wk is fine.

If the crack width is something checked already by RAM (is it checked according to 7.3.4??) why do we design reinforcement according to 7.3.2?

Thanks in advance. Best wishes.

RAM shortening restrain

Adrian Cabello — Tue, 01 Mar 2016 15:09:29 GMT

Dear RAM team. Does RAM account somehow for the effect of restraint to floor shortening, due to columns or cores? (Refer to chapter 3.3 of TR43)

Thanks a lot. Best regards,

RAM Concept steel beams

Adrian Cabello — Fri, 12 Feb 2016 12:46:34 GMT

Dear RAM team,

Is there a way to include steel beams in/under our slab in RAM Concept software and make them work in composite action?

For instance, I've tried to obtain an equivalent RC section but is not easy to predict its behavior because will start cracking. Can I define a linear elastic material or somehow impede cracking of the beam so that I can make the equivalence with the steel element?

Thanks! All the best

RAM - Crack width and shrinkage

Adrian Cabello — Tue, 09 Feb 2016 15:39:14 GMT

Dear RAM team,

From the linear analysis we get a predicted crack width (for the relevant load combination) based on the code formulation. And one of the things RAM does is to reinforce according to the code to keep that crack width.

When we run the Load History processor it develops a material nonlinear analysis where it iteratively cracks the slab until convergence is reached. Do we have access to the information about that real cracks against those predicted in the linear analysis?

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Another question. We want to assess the crack width generated by shrinkage and temperature change. Is there a way to obtain it with RAM similar to CIRIA C660 guidelines?

Thanks, you are the best.

RAM reinforcement Red bars

Adrian Cabello — Tue, 26 Jan 2016 09:57:22 GMT

Dear RAM crew,

I have got a question about RAM Concept. Once my model is done and run I go to “Design Status”, “Bottom Reinforcement” or “Top reinforcement” and I find bars in red. If I activate Controlling Criteria I can find out the governing chapter of the code but not the reason why they turn red. I understand that RAM chooses the amount-spacing of bars following that chapter. Therefore, why are they red? What does it mean?

Thanks

RAM Load History

Adrian Cabello — Fri, 04 Dec 2015 10:42:22 GMT

Dear RAM team,

I’ve got one question regarding the Load History analysis. What is called “Initial load application” is the origin of the load history?

The Initial load application is set by default to 3 days. The curing time by default is 7 days.

This is what is chosen by default by RAM for the rest of the history:

I’d like to go through the history to verify if I understand it.

In a RC slab:

At 3 days we are striking. From day 3 to day 33 we apply the Frequent load. From day 33 to 5033 we apply Q-P load. At day 5033 we apply the Frequent instantaneously and we measure. From day 0 to day 7 we are curing.

In a PT slab:

At 3 days we are striking and applying the postension force. The rest of the history, as per RC Slab.

I deem these default values unrealistic but if I want to modify them first I should be sure that they mean what they mean.

Thanks for your kindness. Best wishes.

RAM question - prestress forces

Adrian Cabello — Wed, 25 Nov 2015 20:05:40 GMT

Dear RAM crew,

I am designing a PT slab to the Eurocode (U. K. National Annex) and I would like to understand the definition of the material given by RAM. It is as follows:

The manual explains:

fse = The assumed effective stress in the strand after all losses.

fpy = The yield stress of the strand.

fpu = The ultimate stress of the strand.

And I don’t understand how can they be correlated to the values given in the TR43 or in some catalogue products, where:

I understand that:

fpu (RAM) = fpk (Eurocode = characteristic tensile strength of prestressing steel)

fpy (RAM) = fp0,1k (Eurocode = characteristic 0,1% proof-stress of prestressing steel)

And the difference between fpy and fse is to accommodate losses (around 30% if I don’t specify the Jacks in RAM) and the limitation to the maximum stressing force (In the Eurocode = 80%fpk and 90%fp0,1k)

Is it correct or what does exactly mean fse respect to fpy and fpu?

Thanks in advance. Best regards!

RAM error message

Adrian Cabello — Thu, 24 Sep 2015 18:18:52 GMT

Dear RAM team,

I am running the deflections check in a RC slab and I have the following alert. What does it mean? Thanks in advance

RAM Punching - Calculation of Beta

Adrian Cabello — Tue, 11 Aug 2015 10:00:40 GMT

Dear RAM crew,

How is RAM Concept calculating Beta for the punching shear check?

I am following Eurocode-2. Beta depends on the eccentricity u/u1* and on the ratio moments to shear. I have a fixed corner column with the following punching reactions and the corresponding Beta.

If I pin the column (I release the moments), I get the same VRd,c, fine. But I get a much higher Beta that I don’t expect.

RAM Column reactions

Adrian Cabello — Mon, 10 Aug 2015 12:00:08 GMT

Dear RAM team,

How is RAM Concept calculating the reactions in the columns?

I've got the following column.

Is the column made out of one single finite element that is connected on top/bottom to the following highlighted node??

In this case, are the reactions the value of the forces/moments at this single common node slab-column or are the reactions integrated somehow across the portion of slab corresponding to the area of the column cross-section? To illustrate the latest, for example, to read the moment in X, would it be the average in the yellow area?

On the other hand, is the column made out of several solid finite elements? In this case, 8 finite elements to define the cross section? I guess in this case the reaction is the integral in all the connected slab-column nodes.

Thanks a lot!!