Played the lectures at 1.25x speed. Completed all the lectures. Best content on internet. Instead of attending online university classes in the pandemic, students should sit patiently and make notes through these lectures.
Resultant force of partly rectangular and partly parabolic portion at a C.G of 0.42 from top and it will be always in compression for concrete upto NA in the normal direction to the plane.
What kind of failure will occur when the section is balanced section? Like for instance for under reinforced section, the deformation in steel bar occurs n a person gets time to vacant the place. In case of over reinforced section, the failure occurs in a sudden collapse manner.
Xu is the depth of neutral axis for any section Xu lim is the depth of balance section. So, For balanced section, xu =xu,lim For under reinforced beam, xu < xu,lim For over reinforced xu > xu,lim.
If we cast M20 concrete in cube and test after 28 days we get failure load as 20 N/mm2 But at the the same time if we cast Mw0 concrete in 3 cuboid of base length 150mm x 150mm but height of 200mm, 250mm and 300mm and we test the 3 cuboid due to slenderness the cuboid fail before reaching 20N/mm2 As the slenderness ratio increase the 20N/mm2(sigma cbc) decrease but maximum decrease is only (2/3 sigma cbc). So we consider characteristics strength as(2/3 sigma cbc) and from this strength we again add factor of safety. ((2/3 sigma cbc) /1.5)
Because if we will assume permissible stress equal to ultimate strength then the structure will fail due to even marginally small addition of load due to various factors but if permissible strength is taken somewhat less than ultimate strength then structure will not fail due to unpredictable addition of small loads
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Played the lectures at 1.25x speed. Completed all the lectures. Best content on internet.
Instead of attending online university classes in the pandemic, students should sit patiently and make notes through these lectures.
if you want to get rid of yawning and boredom while watching this lecture then play it on the speed of 1.25.
Thank you
Faheem Rasheed sahi bola yar
I am still yawning after increasing the speed to 2.
@@4playerchess784 lol
bhai kuch skip to nhi hoga
Sir please explain at 31:09 how we get 1/12, for reminaining Area of parabolic spandrel times C.G. of parabolic spandrel.
1/3*1/4 ... 1/3 is coefficient of area and 1/4 is distance of centroid of remaining area of parabola from N.A
How the compressive force has changed its direction..32:08
Resultant force of partly rectangular and partly parabolic portion at a C.G of 0.42 from top and it will be always in compression for concrete upto NA in the normal direction to the plane.
30:52 how did that 1/12 *0.45 fck*(0.57)^2b term came??
Area of parabola formula
What kind of failure will occur when the section is balanced section?
Like for instance for under reinforced section, the deformation in steel bar occurs n a person gets time to vacant the place.
In case of over reinforced section, the failure occurs in a sudden collapse manner.
No failure. It's an ideal case.
Steel and concrete at same time
Your Video Is Very Useful Sharing Lecture series on Design of Reinforced Concrete Structures by Prof. N.Dhang, Department of Civil Engineering,
plz vice in not available in this video
what is difference between Xu and Xu lim or Xu max?
Xu is the depth of neutral axis for any section
Xu lim is the depth of balance section.
So,
For balanced section, xu =xu,lim
For under reinforced beam, xu < xu,lim
For over reinforced xu > xu,lim.
What is meaning of Xu
we already considering fos 1.5 for concrete but why we have to take 2/3 rd of fck again???? could you please explain???
If we cast M20 concrete in cube and test after 28 days we get failure load as 20 N/mm2
But at the the same time if we cast Mw0 concrete in 3 cuboid of base length 150mm x 150mm but height of 200mm, 250mm and 300mm and we test the 3 cuboid due to slenderness the cuboid fail before reaching 20N/mm2
As the slenderness ratio increase the 20N/mm2(sigma cbc) decrease but maximum decrease is only (2/3 sigma cbc).
So we consider characteristics strength as(2/3 sigma cbc) and from this strength we again add factor of safety. ((2/3 sigma cbc) /1.5)
23:00 how??
By similar triangle, in strain curve.
can someone tell me why is he multiplying with b when the area of rectangle of that stress diagram
0.45fck is the stress and multiplying by area i.e. x*b we get the compressive force
force =stress*area
stress is taken avg. and area you know very well i.e. b*d
we all know whats written . please answer to why .
cool lecture nice subject
Thankyou sir 🙏❤️
So Useful.
What is the difference between xu lim, xu max, and xu???
Sir if it is possible plz make videos in environmental engineering
thnx for this vedio sir
video
Why we assume the permissible stress less than the ultimate stress for design calculations?
Because if we will assume permissible stress equal to ultimate strength then the structure will fail due to even marginally small addition of load due to various factors but if permissible strength is taken somewhat less than ultimate strength then structure will not fail due to unpredictable addition of small loads
thanks for this! :)
nice video thanks a lot
Thank you sir.
is he xplaining anything,or just copying evry bhaluu opps its value!!
He is explaining very clearly. This is RCC class not Mathematics class. You are in B.tech you are supposed to learn basic mathematics before..
He just copy and paste from the pdf... kindly elaborate each and every term
Sounds not available...
🕉️👑💎🪔💝💐🙏🙏🙏
Great
teaching technique is very bad student will not able to understand