About Performance Analysis

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anil2436

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In a 6-storey building under construction, the 4th floor beams do not meet the project concrete class. The building is stopped by the construction inspection. The results of 3 cores taken from the 4th floor beam concrete are 20.3 N/mm2 on average. Project concrete class c30 Do you think a performance analysis can be made in the building by assuming that the beams on that floor are C20 without breaking the beams on this floor and predicting that C30 will be poured on the upper floors? Or is the performance analysis only done for the currently completed buildings? Thanks in advance for your answers. I need help urgently.
 
Hello, my suggestion. To assume the concrete value is C20; Evaluation is made according to TS EN 13791. sample evaluation: page 32 will be considered. (Note in the example here: k coefficient has been taken as 4 but 7 should be taken.)
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Suppose C20 provided after this verification. Analyze the problematic column, beam, curtain and slab as a new building by changing the concrete value and making it C20. If it doesn't give an error, no problem. If it fails, a: the faulty parts are broken and rebuilt, b: reinforcement is made. Take it easy Unver ÖZCAN
 
First of all, thank you for your help, Mr. Ünver, but only the 4th floor beams of the building do not provide the Project concrete class (C30). The compressive strengths of 3 core samples (75x75mm) (length/cap ratio 1) taken from this floor are respectively 20.7 -19.6 - 20. It is calculated as .7 mean.20.3 N/mm2. Since the wet concrete cube samples for the lower floors ensure the project performance, no core is taken. The question here is, can the project designer accept the 4th floor beams as 20.3×0.85 = C17 and perform a performance analysis by predicting the unfinished and completed floors as C30, or how many can he accept the 4th floor beams in the project according to tse EN 13791 and what kind of path can he follow? . Good work.
 
My suggestion: --The number of cores taken here is very low --According to this number of cores, there is an average of (20.7+19.6+20.7)/3=20.3 N/mm2 -- According to TS 13791 0.85*fck,is=fm(n),work- k or 0.85*fck,is=fis,lowest+4 should be taken as the lowest k=7 from the table 20.3-7=13.3 N/mm2 19.6+4=23.6 N/mm2 concrete value should be 13.3 N/mm2.(number of cores) If it is more, it will be higher.) --In this case, since you cannot use concrete under C20, you will either break and rebuild the places that do not provide the concrete value (if C20 came out, you could check it by calculation. If the upper floors were poured, it would not be broken and rebuilt.) or you would strengthen. -- If you decide to strengthen, you will determine the concrete calculation value for the static calculation by coring the building according to the limited, medium, comprehensive condition according to TDY 2007 article 7.2.5.3-7.2.6.3. (If concrete values are known on other floors, it can be taken from the floor that does not provide the concrete value.) --Concrete values are below C30, you will enter the value you found on the floor that does not provide the performance analysis. --Generally, in the performance calculation made according to TDY 2007 rules, there are big screen additions. It's not economical after all. It may be more economical to break up and rebuild the wrongly poured solid. Unver ÖZCAN
 
Unver Bey, there is only a problem with the beams of the 4th floor. According to the above calculations, it seems obvious that it will be below C20 in the performance analysis. The contractor does not want to save by calculation, that is, to slaughter. Is it not possible to increase the number of cores and calculate as C15? (with k=5) If it doesn't give reinforcement on that floor, is the program suitable? Now it calculates life safety according to C17 presented by the author.
 
Or would it make sense to increase the average by taking cores from the lower floors that provide the project performance and to calculate by decreasing the k value? that is, the cores taken from the lower floors will provide C30, so the average will increase and the k value will decrease. Am I thinking wrong? Thus, can acceptance be made by bringing those multiples to a value above C20, for example? Best regards.
 
MY RECOMMENDATION: " Mr. Ünver, there is only a problem in the beams of the 4th floor. We have broken the productions on the upper floor. According to the above calculations, it is obvious that it will be below C20 in the performance analysis. The contractor does not want to save by calculation, that is, he does not want to make a demolition. k=5) If it does not give reinforcement at that floor, would the program be appropriate? Now it calculates life safety according to C17 presented by the author." (Important note: It is not used in TSE EN 13791 performance calculation.) Core When the number is increased (according to TDY 2007 article 7.2.5.3-7.2.6.3) the standard deviation coefficient will decrease, so the calculation concrete value automatically increases. According to what you said, if this concrete value you found is C17 (by entering C17 for lower floors and C17 for upper floors.) and if it provides life safety as a result of performance calculation for the whole building, it is ok. "Or would it make sense to calculate the average by raising the average and decreasing the k value by taking cores from the lower floors that ensure the project performance? That is, the cores taken from the lower floors will provide C30, so the average will increase and the k value will decrease. Am I thinking wrong? Can acceptance be made by putting a value above ? Sincerely, " Such an approach would not be correct. We cannot accurately determine the concrete value on that floor. Unver ÖZCAN
 
There are only problems with the beams of the 4th floor in our building, there are no problems with the columns and curtains. As I said, the values of 3 samples taken are 20.3 N/mm2, so under these conditions, do you think that me should be done without breaking the beams on this floor? The section of the regulation you mentioned mentions columns and curtains. There is no explanation for beams.
 
MY RECOMMENDATION: "There are only problems in the beams of the 4th floor in our building, there are no problems in the columns and curtains. As I said, the values of 3 samples taken are 20.3 N/mm2, so under these conditions, do you think it should be done without breaking the beams on this floor? he talks about columns and curtains, there is no explanation for beams." According to me: TDY 7.2.6.3 should also say that if necessary, cores can be taken from beams. In a similar situation, TDY 7.6.2 exists for reinforcement realization coefficient. He counted the columns and beams, not the curtains. Since the problem is with your beams, you need to work on the beam. AFTER THAT INFORMATION. CONCLUSION: If the concrete values are known for the performance calculation on the lower floors (IF THERE IS SUFFICIENT NUMBER OF SAMPLE SAMPLES IF THERE IS C30), if we find the concrete calculation value for three samples on this floor according to TDY, you can get an average concrete value of 20.33-0.63=19.7. Unver ÖZCAN
 
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