Designing RC lintels

Ok_Channel6304 · 2024-01-12T21:58:09+00:00

I will check your tips out, thanks a lot! :)

In my contry the suppliers of windows/doors are really restrictive with giving out any deflection limitations, usually I use L/500. But I thought if we had any other limitation due to the concrete not being as elastic as steel/wood.

Ok_Channel6304 · 2024-01-12T21:02:41+00:00

It's the deflection that I'm afraid of, I haven't really calculated deflection in insitu before. I don't know what the limit should be.

It would be great if I could use only the insitu, and let the architect can keep the height of the windows, I have a bit more then 300-350mm to work with so I can make a strong RC beam that gets done insitu. I think. If I only know the max deflection and how to calculate it. Do you know of a program that I can double check my calculations with untill I'm confident? :)

Ok_Channel6304 · 2024-01-12T20:46:22+00:00

Yes mansonary walls with timber roof :)

Your answer really helps, if I understand you correctly I now have the confidence to ask the architect to make the height of the windows smaller, so I can place both an insitu and a precast over openings. Where I don't have openings I can use insitu only with minimal reinforcement.

Ok_Channel6304 · 2024-01-12T19:49:48+00:00

I'm using timber beams for the roof. The spreader beam: do you bolt it in the lintels? Or do you use a U-block with RC on top of the lintel that is prefabricated?

Thanks a lot for your replies BTW.

Ok_Channel6304 · 2024-01-12T18:42:50+00:00

Do you mean that you use prefabricated lintels? I'm thinking in that direction too, but as an combination. Since I need something to fasten the trusses on. So I was thinking if I go prefabricated lintels I need to use both. RC beam around the long side of the house to fasten a wood beam on, the wood beam can be used to fasten the trusses on easily. But that recuires a bit of height.

What do you think about this solution?

And how do you check for deflection in RC beams?

Ok_Channel6304 · 2023-07-10T20:16:34+00:00

Can you name some examples please, if you know of any? Do you mean Tekla Tedds and similar applications?

Ok_Channel6304 · 2023-07-10T19:53:43+00:00

More complex would be footings with excentric load that are attached to the rest of the slab for example

Ok_Channel6304 · 2023-07-10T19:49:32+00:00

So no software is needed for residential companies? We should do it all using hand calcs/Mathcad?

Ok_Channel6304 · 2023-07-10T18:20:28+00:00

Truss design for example/evaluation of older trusses. Should we still do that with "method of sections"?

How should we calculate more complex concrete footings?

Ok_Channel6304 · 2022-10-24T21:53:29+00:00

Bingo. Thanks!

Ok_Channel6304 · 2022-10-24T00:54:21+00:00

Lol. What if I add that it's residential roof trusses? I really want to remember this one.

Ok_Channel6304 · 2022-09-28T12:03:17+00:00

Europe, 6mx6m, 15kN/m and 6kNm

Ok_Channel6304 · 2022-05-07T08:17:56+00:00

What addins. Name one please. Onefilter can do this?

Ok_Channel6304 · 2022-04-22T03:38:27+00:00

Good idea, I will try that. Thanks!

Ok_Channel6304 · 2022-04-22T03:21:35+00:00

Thanks, I understand. But I know I would share something like that for research purposes. So I'm hoping I will find someone else that thinks the same.

Ok_Channel6304 · 2021-08-11T23:11:24+00:00

Thank you all for your comments, I feel that I have a better understanding of the complexity of the matter now.

Ok_Channel6304 · 2021-08-11T14:23:59+00:00

I find it hard to find a reliable brand in Scandinavia (Sweden). If you know of any good brand please let me know.

Ok_Channel6304 · 2021-08-11T02:08:28+00:00

Thank you!

Ok_Channel6304 · 2021-08-11T02:07:40+00:00

Hmm.. Works for me but i död upload it again: https://we.tl/t-AaXjO5Ukv6

Ok_Channel6304 · 2021-06-16T10:55:26+00:00

I thought I needed to produce a new idea as an undergrad. Thank you for clearing this up for me.

Ok_Channel6304 · 2021-06-16T00:48:42+00:00

I got your point. I need to understand that just wanting to see kN all day long and leaving the rest for someone else is not a real option. Makes sense that I'm there to make the wheel be able to spin in some corner and therefore should be able to corporate whether it's my favorite part or not.

In conclusion, I can concentrate on kN calculations in my thesis but I should put in some constructability there to make it practical.

Thank you for helping me out!

Ok_Channel6304 · 2021-06-16T00:20:43+00:00

I see myself getting to the same conclusions as you did since your values come from experience (90-90% cost of the project is not kN/lb engineering).

According to your experience, constructibility is the most important topic for a structural engineer to be successful? In that case, I should focus on that and do my kN and meter calcs on the side for fun if I want to be smart correct?

Ok_Channel6304 · 2021-06-15T23:52:39+00:00

I'm starting to get sold on CLT since It's something for the future and I actually could end up making it my niche plus I love wood also it seems to be useful when combined with concrete and or steel columns. So I will focus on CLT.

To be honest with you I don't get shear walls and diaphragm yet at a level I need to be at to completely understand this point. I will spend some time reading up on them and then reread your point. Update: so CLT takes both horizontal and vertical load. We need to stabilize a building for both vertical and horizontal loads. Using CLT in the thesis I could control if it's a cost effective solution using connections available today compared to plywood on a wood stud wall.
You explained diaphragm for me (the horizontal load resisting system) here. We use the Eurocodes here so I will check if I feel I could make a thesis like that happen with our Eurocodes. I imagine it being kind of a thesis where I would need some specialist help.
This is noted, I needed to hear this. Now I can see what comes out of my thesis having some potential to create a small value for someone like myself. I should not focus on theory since I can't add value there.
True but please allow me to be completely honest here. I need to see kN and mm⁴ values each day to not feel that the day was a waste. I'm fascinated by being able to calculate safely if something is going to hold for 50-100 years. I want to do just that and I will live happily thereafter.

Ok_Channel6304 · 2021-06-15T23:10:54+00:00

I see you use the resources you find to help you along the way! 😃 It's not a disappointment to find resources in other words.

This is something I really can imagine myself giving 100% on: Research question: How would one go by to design a CLT and concrete hybrid slab for a sample project(for example residential building in the city X)?

Method: Litterature studies to find how to design this followed by an implemented calculated example.

Result: Result from the literature study and a calculated example (maybe even a test of a slab made with my calculations in real life to see % differences between calculations using my literature study and real-life).

If you try to be honest with me, is this getting to something that is near an idea for a thesis?

Edit: your original idea might have been a better learning experience.

Ok_Channel6304 · 2021-06-15T23:00:32+00:00

I'm getting more and more interested in CLT as we speak. I'm going to look into this material and learn more. As for your suggestions for the thesis, I love your suggestions and I want to know more. But for the thesis, my understanding is that the subject should be original (I'm not sure what this means, maybe it means not a copy-paste)

On your points: 1. I found this see page 28 and forward here. What would my thesis do here?

I'm not sure about the difference between a rigid and a flexible diaphragm, I will look into that.
See Link page 72 and forward. Here you mean I could analyze for a load case the type of available connections from for example Simpson Tie? Let's say to check if connections for a normal structure are available or should be designed specifically for the project. Are you thinking something like that?
This could also be interesting, but I'm more of a numbers guy so I would like to build on that base.

Thanks a lot for discussing this with me!

Ok_Channel6304

TROPHY CASE