retrofit curtain

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teknoadam

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1st question hello, does idecad give a critical wall height in the reinforcement curtain that continues throughout the entire building or not, is it necessary to give a critical curtain height in the reinforcement curtains in the drawings? (along the critical height of the wall, giving 2 floors according to the header on the normal floor, etc.) 2nd question: For example, the concrete strength of the current situation while the reinforcement curtain is being laid c24 (concrete strength as a result of calculations) Is it necessary to jacket the columns to which the curtain is attached, can we get your opinions on this matter?
 
Dear Teknoadam, 1- Reinforcement curtains are also subject to normal reinforced concrete curtain rules. Therefore, the critical pitch rules are also valid. 2- When the reinforcement walls are modeled between the existing columns, the compressive and tensile forces increase in the header areas, especially in the walls that try to bend. Existing end columns connected to the reinforcement curtain with anchors are also affected by the cap areas, so they participate in these strains just like they are a part of the cap area. There are many examples of this situation in the source. You can find similar comments in the books of Z. Celep, N. Kumbasar, G. Özman. In the new regulation of 2018, there are recommendations in this direction in the section of reinforcement curtains. In this way, it is ensured that the sheathing and reinforcement curtain work together and the load transfer of the existing columns. High quality concrete is not always a guarantee that the end columns can meet these effects. Section sizes, reinforcement and amount of wrapping are effective in this. Since these columns and beams on shear walls can be easily modeled in idestatistics, you can see the status of the end column by entering the existing reinforcement and wrapping properties in these columns. If you ask is it always a must? It is not a rule written in the books, but my suggestion is to sheath it in any case if it gives collapse in these columns in the ide static analysis. In general, the collapse mechanism works as follows. In case the axial load ratio Nk/Acfm ratio exceeds 0.7, r limit=1 decreases and in case of r>1, it gives failure. The only solution to this is sheathing. If jacketing is required on the end column on one side of the reinforcement curtain, both end columns are jacketed to ensure symmetry. The floor that requires a coat and those on the lower floor are sheathed. Climbing to an upper floor is necessary for torque transfer continuity. Although it does not cause collapse in idestatic, my preference is to jacket all curtain end columns under concrete quality C14. Because under this concrete quality, the load transfer efficiency of the anchors decreases. In some programs, you can hear the criticism that the curtain end columns are not sheathed. The only reason for this is that there is no possibility of modeling the curtain end column and taking its drawings in those programs. I hope I was able to answer your end.
 
Your answer is quite understandable. I also have a question, if we put mantles on these columns, then we do not need to put a cap on the reinforcement curtain. In addition, I have seen hundreds of reinforcement examples so far, the critical curtain height of the reinforcement curtains is not given. In the directive 2007 3.6.2.2, the critical curtain height in the curtains continuing throughout the building should be increased in most high-rise buildings, but my friends working at idecad do not give critical curtain heights, can I get your opinion on this issue?
 
Dear Teknoadam, Sheathing the existing end columns of the reinforcement curtain does not replace the curtain cap. Jacketed columns may not always be in sizes that will meet the curtain head conditions. As I mentioned in my previous e-mail, the purpose of sheathing the end columns is to strengthen the end columns damaged due to increased effects and to strengthen the existing structure-reinforcement curtain connection. In the 2007 regulation, curtain caps are also arranged as curtain cap reinforcement is required in any case. Ide identifies the critical height of curtains in both static normal curtains (continuing throughout the building) and reinforcement curtains, and if you make the head zone adjustment automatically, it arranges the head contours and reinforcement accordingly. Indeed, that is it. Our project group has designed thousands of building reinforcement curtains. It's all like this.
 
STRENGTHENING CURTAIN greetings to the idecad family. here is my question. There is an opening of 14m (workshop of a school) here. I need to put a reinforcement curtain here, but I cannot put it in the middle because it is a usable area. If I throw a curtain for 14m (to work from column to column), it seems to be an unhealthy process, but if I leave one end free (if we throw the reinforcement curtain 3-4m) and connect one end to the column to the beam, will I see the benefit of this curtain as a reinforcement curtain? I am attaching a picture
 
Mr. Teknoadam, piece of curtain can be thrown. Reinforcement curtains do not have to be column-to-column. However, in this case, there will be excessive strain on the beam that is connected to the curtain from the half. This beam may also need to be checked and reinforced. There is another issue I would like to ask about this structure before that. Is there a reinforced concrete slab that will form a rigid diaphragm on the structure? If not, strengthening with curtains is not the right method for this type of structure.
 
Is the floor concrete or steel? If it is concrete, how is the beaming? If it is steel, what kind of scissors etc. Need more detailed information about flooring. Photographs etc. only the plan is not enough. Before deciding on the reinforcement system, the behavior of the structure should be understood. But these are my problems. My question is can only half a screen be shot, the answer is yes.
 
roof slab and beam this way. I also came across another type, the distance from column to column is approximately 26m, beamed floor is passed (gymnasium) and the distance between the bottom of the beam and the foundation is about 10m. Here, along the critical height of the curtain wall, a very large curtain cap comes out when it conforms to the directive and the thickness of the curtain exceeds the column. My question is, we have increased the thickness, but this time, if we move away from being a curtain due to the requirement of directing, will we still have a headline (let's think of 30/210 curtains, but when the floor height/20 is 50 cm thick, it ceases to be a reinforced concrete curtain)
 
Mr. Technoadam, your main problem here is not the size of the curtain. The wall thickness can also pass through the column, which is a possible situation. In these cases, we usually coat the column as well. However, if I have not misunderstood the photographs before that, we are talking about a two-storey building with variable column sections, inclined ceiling slabs and beams. If you are not experienced in the performance analysis of these types of structures, I recommend you to get professional support first. Below are the main questions for which you will seek answers. Because; 1- We cannot model a column with variable cross-section in idestatic. What are your modeling assumptions here? 2- A structure with a sloping floor can be modeled and designed in Idestatics, but there is a rigid diaphragm behavior in the performance analysis assumptions of the program. How did you model the floor and joists? Have you examined how rigid the diaphragm behavior of your model is? 3- Where does the flat floor that I see in the second photo belong to? If there is such a flat floor in between, what is the structure of this floor? 4- What is the concrete quality and reinforcement status of the building? In this type of structure, it is generally not possible to strengthen only with curtains. You may also have problems with the columns.
 
Here, the flat-looking floor is connected with inverted reinforced concrete beams (one-way), my main question is as follows: Suppose I'm building a reinforcement curtain in a building like this one with a very high floor height (like 10m), but as per the 2007 directive, a very thick curtain end and body-like will come out along the critical curtain. Since the width of the screen has increased (assuming I put 30/210 screens here), this screen will be a column that will cease to be a screen due to the aspect ratio. then, shall I design this reinforcement curtain as stated in the directive or will I make it like a column because this curtain has thickened, I hope my question has been understood.
 
Dear Technoadam, Of course, I understood your question, but I wrote that this is not your main problem in this structure, the main problems you need to solve before coming here. The answer to your question: According to the regulation, elements whose dimensions are columns are equipped and analyzed like columns. Elements in curtain sizes are equipped as curtains.
 
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