That's the moto of the channel, channel is open for all civil engineering fraternity, right from student community to working professionals, I am very happy this video was useful for you, kindly keep supporting by sharing with your civil engineering friends
Good video.......The ratio of strength of concrete in beams, columns, slabs, etc. on site to the strength of laboratory cylinder is approximately 0.85. That means site concrete will approximately show 85% of laboratory cylinder strength for the same concrete. This is because of quality control, size effect (as the actual rcc elements are bigger, fracture mechanics theory prevails & governs); moreover concrete is brittle in nature (actually quasi-brittle). So, actual strength on site = 0.85fc......Again, the ratio of cylinder strength (fc) to cube strength (fck) is approximately 0.8, i. e. Cube shows approximately 80% of strength as compared to cylinder (due to various reasons)....So, fc= 0.8fck.....Now, strength of concrete on actual site is 0.85x0.8fck = 0.67 fck.......Divide it by FOS of 1.5, it becomes 0.45fck.....However, as a matter of fact, concrete is such a complex, erratic, heterogeneous & non isotropic material that all these theories are based on certain experience as well as assumption. So, much research needs to be done yet.
Hello, I am a simple teacher who loves to teach and spread my knowledge whatever i know, Calling me God is all your love but i am a simple teacher, your comment will boost me to do more videos and help you, all the best
Sir thankyou for this amazing lecture. But I have a doubt sir why stress strain curve for concrete for characteristic curve , curve for structure and design curve starts from different positions from orgin itself but not so in steel ?
At after about 4 minutes, your are seen saying that stress is increasing linearly , that is wrong but you should say parabolically instead of linearly.
0.67 is not partial safety factor..it is a coefficient. Meaning that if cube strength of concrete cube is 35N/mm2, the equivalent design strength for flectural members is 35x0.67=23.45N/mm2. The only F.O.S for the concrete is 1.5. Meaning that the coefficient of 0.67 is not a safety margin.
Sir i got one doubt.. Now as you explained we saw that we have to decrease the strenght of concrete in design WHY ?????? But at the same time we are saying that the concrete has more uncertainities on site for example( poor preperation), now these two points i mentioned contradict each other??? Should not we have to increase F. O. S for concrete???????? Then why we keep decreasing its strength for example from 0.67 fck to 0.45 fck??????
0.45 fck is for factored load ..FOS of 1.5 will be applied on 0.45fck as well...so actual permissible load on structure will be 0.3 FCK......we consider less strength because if we apply less load.. structure will be safe for same concrete and steel ...general public will only be allowed to put load as 0.3 FCK...that's the only reason gentlemen ..house made by uneducated contractors doesn't fall down or collapse...but fail in serviceability in long term....that's how corruption begins ...Engineers and contractors take bribe bcoz of that 3.33 FOS on concrete....hope it will help. 🦺👷🙏
fck is the compressive STRENGTH of concrete. by using 0.67 and dividing by 1.5 safety factor, you are basically considering it to be weaker in your calculations than it actually is example: actual compressive strength that you got by testing of concrete is 25 MPa, by using 0.45 factor, 25 x 0.45 = 11.25 MPa. so you are now considering the 25Mpa strong concrete to be only 11.25 MPa strong in your calculations, which will show failures at lower loads than in reality, thus we made the design stronger. hope that's clear..
Sir i have a question, in diploma I am understanding everything easily. I got the subject basics easily. But my problem from 10th is maths , then in diploma too it was maths. Now what I want to ask is, 1) I will get in btech though leet. And maths subject there is same as 12th maths? 2) second will I be able to easily catch up with the students and subjects there? 3) Is btech going to be hard for me if all my diploma subjects are pretty easy to understand? Please reply no one in my family is a enginner from Diploma to btech. Either they did btech in 2000 around, and other are doctor and teachers
Hello, whatever you do your hardwork will play an important role in your success, and one thing is sure that students who do well in diploma will do very well in B.Tech. So work hard and achieve your goals and taste the success, all the best keep watching and keep sharing
Correct reason of introducing partial safety factor(PSF) of 1.5 is not what you are saying in this video. first thing is value 1.5 is an arbitrary one and there is no reason that why this values is kept exactly equal to 1.5. Now coming to main point . Reason of introducing PSF is the possibility in variation in quality of concrete to be produced at site. Quality of concrete is more prone to be varied on site due to variation in quality/quantity of ingredients of concrete ( cement, aggregates, water, admixtures etc ) and also due to variation in process (e.g. mixing time, labour rest ,possible labour problems, atmospheric condition, surrounding environment etc ) by which the concrete is produced on site. PFS of 1.5 was introduced during those era when there was no RMC and concrete was produced on site only , but nowadays when RMC is made available easily , this factor should be reduced accordingly where RMC is to be used to attain economy in construction. On other side, PFS for steel is 1.15 because steel is manufactured in plant where better quality control on manufacture of steel bars can be assured . Reliability of overall quality control measures on production of concrete and steel are different because concrete is produced at site ( if RMC is not used) while steel bars are manufactured in steel plant. At one instance of video , you have used word " construction of concrete" . this word is not a proper word , you should have used word 'production of concrete ' instead. OK 😂😂
Super sir, I have 5 yrs experienced structural engineer, but now only learnt from ur channel only in stress strain curve...
That's the moto of the channel, channel is open for all civil engineering fraternity, right from student community to working professionals, I am very happy this video was useful for you, kindly keep supporting by sharing with your civil engineering friends
Good video.......The ratio of strength of concrete in beams, columns, slabs, etc. on site to the strength of laboratory cylinder is approximately 0.85. That means site concrete will approximately show 85% of laboratory cylinder strength for the same concrete. This is because of quality control, size effect (as the actual rcc elements are bigger, fracture mechanics theory prevails & governs); moreover concrete is brittle in nature (actually quasi-brittle). So, actual strength on site = 0.85fc......Again, the ratio of cylinder strength (fc) to cube strength (fck) is approximately 0.8, i. e. Cube shows approximately 80% of strength as compared to cylinder (due to various reasons)....So, fc= 0.8fck.....Now, strength of concrete on actual site is 0.85x0.8fck = 0.67 fck.......Divide it by FOS of 1.5, it becomes 0.45fck.....However, as a matter of fact, concrete is such a complex, erratic, heterogeneous & non isotropic material that all these theories are based on certain experience as well as assumption. So, much research needs to be done yet.
Thank you for this explanation. Saved my 12 minutes.
Sir you are really giving very knowledgeable and specific content , thank you so much sir.
Thanks and welcome, so nice of you, keep watching and sharing
Sir thank you for clearing my doubts
Continue this brilliant work 👏 🙌
Thank you so much, keep watching
Very good explanation sir
Thanks and welcome, keep watching and keep sharing
Excellent explanation
Thank you sir, keep watching and keep supporting
Very nice explanation on very important topics. Thanks a lot.
You r the god sir😃🙏
Hello, I am a simple teacher who loves to teach and spread my knowledge whatever i know, Calling me God is all your love but i am a simple teacher, your comment will boost me to do more videos and help you, all the best
Very informative video sir.... i want lecture for stress stain curve of steel
Amazing lecture Sir 👍👍 Thank you very much Sir 🙏 🙏
Great work. 👍
Amazing lecture sir 😊
Thank you, keep watching and supporting
well explained sir. Thank alot sir
Thank you so much, all the best, keep watching
Waah grt sir....very conceptual 👍👍
Very Useful, Thanks Sir.
You are most welcome, keep watching and sharing
Excellent sir..
Thank you so much, all the best, keep watching
Pls consider to put videos on manual design of G+1 building including analysis...
Very informative video sir thank you
Most welcome, keep watching and keep supporting
Very helpful ..nice explanation
How this value 0.002(Strain) came?
Very informative thank you
great work 👏
Thank you for watching
very informative and very useful
Very informative and we'll explained.
Please make a video on bridge design.
Noted, Will try it
Very helpful, Thank you
Sir thankyou for this amazing lecture. But I have a doubt sir why stress strain curve for concrete for characteristic curve , curve for structure and design curve starts from different positions from orgin itself but not so in steel ?
Superb sir
Thank you
You're welcome
At after about 4 minutes, your are seen saying that stress is increasing linearly , that is wrong but you should say parabolically instead of linearly.
Thank you so much sir
Sir, how principle of superposition is valid if the curve is parabolic. we are designing all the structures based on this principle.
Thanks
Welcome, keep sharing, all the best
Sir do you have any videos in udemy or in any app. Pre recorded
No i am not there in udemy, my all videos on youtube and free
@@structuralanalysisanddesign thank you sir. Respect you🙂
@@kennyomega8937 Thank you so much for following
@@structuralanalysisanddesign it's my pleasure. Please upload such useful videos sir.
@@kennyomega8937 Will come up with more informative videos soon
Amazing
Thanks a lot, keep watching and sharing, all the best
Is the strain (dl/l) 0.002 and 0.0035 same for any grade of concrete?
Sir please make vedio on irrigation and bridge drawing
Noted, will try
Sir stree-strain curve for mild steel to nhi bataya
0.67 is not partial safety factor..it is a coefficient. Meaning that if cube strength of concrete cube is 35N/mm2, the equivalent design strength for flectural members is 35x0.67=23.45N/mm2. The only F.O.S for the concrete is 1.5. Meaning that the coefficient of 0.67 is not a safety margin.
Sir can u Explain
The Stress blocks parameters
Too good
Sir i got one doubt.. Now as you explained we saw that we have to decrease the strenght of concrete in design WHY ?????? But at the same time we are saying that the concrete has more uncertainities on site for example( poor preperation), now these two points i mentioned contradict each other??? Should not we have to increase F. O. S for concrete???????? Then why we keep decreasing its strength for example from 0.67 fck to 0.45 fck??????
0.45 fck is for factored load ..FOS of 1.5 will be applied on 0.45fck as well...so actual permissible load on structure will be 0.3 FCK......we consider less strength because if we apply less load.. structure will be safe for same concrete and steel ...general public will only be allowed to put load as 0.3 FCK...that's the only reason gentlemen ..house made by uneducated contractors doesn't fall down or collapse...but fail in serviceability in long term....that's how corruption begins ...Engineers and contractors take bribe bcoz of that 3.33 FOS on concrete....hope it will help. 🦺👷🙏
fck is the compressive STRENGTH of concrete. by using 0.67 and dividing by 1.5 safety factor, you are basically considering it to be weaker in your calculations than it actually is
example: actual compressive strength that you got by testing of concrete is 25 MPa, by using 0.45 factor, 25 x 0.45 = 11.25 MPa. so you are now considering the 25Mpa strong concrete to be only 11.25 MPa strong in your calculations, which will show failures at lower loads than in reality, thus we made the design stronger. hope that's clear..
👍🏻perfect
Sir,what is the shape of idealised stress strain of concrete
Parabolic or rectangular parabolic
th-cam.com/video/TRS3Zx-Mt-Q/w-d-xo.html
1.5 is a " partial safety factor" , not a "factor of safety". both word are different, and has different interpretation. 😀
One small correction in my comment: Read it as, cylinder strength is apprpx. 80% of cube strength.....
nice
Sir i have a question, in diploma I am understanding everything easily. I got the subject basics easily. But my problem from 10th is maths , then in diploma too it was maths.
Now what I want to ask is,
1) I will get in btech though leet. And maths subject there is same as 12th maths?
2) second will I be able to easily catch up with the students and subjects there?
3) Is btech going to be hard for me if all my diploma subjects are pretty easy to understand?
Please reply no one in my family is a enginner from Diploma to btech. Either they did btech in 2000 around, and other are doctor and teachers
Hello, whatever you do your hardwork will play an important role in your success, and one thing is sure that students who do well in diploma will do very well in B.Tech. So work hard and achieve your goals and taste the success, all the best keep watching and keep sharing
First View
Thank you Gagan, keep watching
Correct reason of introducing partial safety factor(PSF) of 1.5 is not what you are saying in this video. first thing is value 1.5 is an arbitrary one and there is no reason that why this values is kept exactly equal to 1.5. Now coming to main point . Reason of introducing PSF is the possibility in variation in quality of concrete to be produced at site. Quality of concrete is more prone to be varied on site due to variation in quality/quantity of ingredients of concrete ( cement, aggregates, water, admixtures etc ) and also due to variation in process (e.g. mixing time, labour rest ,possible labour problems, atmospheric condition, surrounding environment etc ) by which the concrete is produced on site. PFS of 1.5 was introduced during those era when there was no RMC and concrete was produced on site only , but nowadays when RMC is made available easily , this factor should be reduced accordingly where RMC is to be used to attain economy in construction. On other side, PFS for steel is 1.15 because steel is manufactured in plant where better quality control on manufacture of steel bars can be assured . Reliability of overall quality control measures on production of concrete and steel are different because concrete is produced at site ( if RMC is not used) while steel bars are manufactured in steel plant.
At one instance of video , you have used word " construction of concrete" . this word is not a proper word , you should have used word 'production of concrete ' instead. OK 😂😂
🙏👏🙌🙌🙌🙌🙌🙌
Thank you for watching
Superb explanation
th-cam.com/video/TRS3Zx-Mt-Q/w-d-xo.html
Amazing explanation