Big Mistake in Cantilever Beam on Site

[@Patrycjusz211]

I think that your critique might br omitting the constructability angle. Consider this; The bottom bars might have been designed like that for uniformity and ease of construction. 5 feet of a single #16 bar might not be worth differentiating the top and bottom teinforcement of the beam, especially if its a part of a continous bea. 3#16 bars on the top could be sufficient to carry the negative moment. The bars on the bottom, however, might just be a continuation of the reinforcement of the neighbouring span left like that on purpose.

[@KAMRANKHAN-xf7iq]

So in case of cantilever the hogging occurs which means the tension in the upper zone and compression in the lower zone of beam that's why we always provide rebars especially in tension zone as steel can carry very powerful tensile loads without failure. We also provide steel in compression zone also but we use it very less as concrete is sufficient to carry the highly compressive loads and stresses. Just try to avoid or make less rebars in compression zone! What about torsional stresses? Where we will give torsional rebars if there is a chance of torsion???

[@sammario3633]

I am a structural engineer. I think your structural engineering knowledge is based on the office designs. The construction site people may be not qualified as you. They provide same steel at top and bottom in a cantilever because to avoid mistakes of placing smaller diameter bars at top. Also it will cost minimum compared to the failure of the cantilever. Stirups no need to be closer at the support. Provide what is required. People do mistakes at site. Think practical than the book work.

[@ferbllaneta1695]

Hi, i think you should consider the 135° bend of stirrups.

[@paolopablo5292]

Another method in the cantilever beam is to provide hanger rebar along the junction. The spacing of the stirrups along the junction should be nearer with 50mm space, then 100mm, then at the end with 150 to 200mm.

[@pawanpopli1428]

How can we use vibrator with 2" stirrups spacing, its not practically possible

[@hamidafridi98]

Sir try to point out such mistakes on site..it's really helpful

[@Knowledge-bw6cx]

Good thought.

[@mob-dee4210]

It’s what he just did

[@hamidafridi98]

@@mob-dee4210 of course but what I mean to say is to keep it up

[@i3_13]

Plot twist: he's the engr in charge

[@proyekmania]

Hahahahaha

[@deepakj7256]

Good one 😹

[@zannalih]

Hahahaha 😂

[@paulphoenix8673]

an idiot engineer

[@amsterdamn9236]

Thats the result of online class instead in actual

[@eWorm3249]

Is cutailment just to economise or is it really necessary?

[@sadiq5681]

So how many inches does floor beams to be the intervals

[@susaankafle197]

Bars taken from continuous beam connected to the cantilever portion should be fine, so regular rebars of 3 on top and bottom shouldn't be a problem, two extra bars at the middle might be torsion bars but for that depth might not have required so yes could have been used at the top. Stirrups of 4" spacing should also be fine but considering the 5' of cantilever, shorter spacing would be better, but I've never seen use of just 2" stirrups spacing even for any cantilevers.

[@ganiputra3390]

Is it possible to pour up concrete with stirrups by 2 inch? Based onACI I think its 4 inch not less than that.for concrete workability

[@liyaqathali2648]

@@ganiputra3390 yes,2 inch spacing is too short for concrete pouring/workability. 3-4 inch is good.

[@ganiputra3390]

@@liyaqathali2648 thank you profesor

[@faisalkhan3825]

You are doing really good work, I appreciate your work

[@sangeenzaman3026]

Isn't it overhanging portion of beam?

[@AftabAlam-ok5jx]

what about the uniformity of cover over the cantilever span as we see the transeverse bar at joint has pass over the bar of cantilever beam?

[@jjulianasociados2511]

Rebar in middle height of section could be torsion reinforcement. Cantilevers should be designed to withstand tension on both top and bottom in case of moment reversal and vertical seismic forces. Continuous rebar over columns should be sufficient for development length if amount of steel rebar is correct. Hooks on hoop reinforcement should be 135 degrees and spacing should be checked for VP.

[@KakashiHatake-fh5xs]

So the bars on the side of the beam are required or not, because most of the construction they provided

[@siddheshwagh9770]

What about link joint which is at top side ?

[@fayazkhattak6619]

In cantilever stirrups hooks should be at compression zone.

[@huvetolohe3511]

Really helpful,guide us in every corner .Nagaland

[@sampangibalakrishna5276]

Sir why we are treated as tension at top in cantilever beam..

[@pranjalsaxena4573]

Because concrete is weak in tension and in cantilver beam at the top of the neutal axis is in tension and below that is compression.... to make it safe from failure more r/f is provided on the top side.

[@Knowledge-bw6cx]

Because usually we have negative moments in the upper zone of cantilever beam .

[@schmooverboover]

I'm quite scared about the structural capacity of buildings in your country/area after seeing this amateuristic way of correctly determining the needed amount of reinforcement...

[@vangcruz4442]

Just cut one steel rod from the bottom then there will be more steel rod on top and cut the two side rod since it is not needed.

[@mohamedmansoorali5310]

You cannot cut the bottom bars just like that bro. Those things should be only after Structural Engineer's intervention.

[@vangcruz4442]

@@mohamedmansoorali5310 I thought the structural engineer was suggesting that there are one to many on the bottom and the two sides are not needed.

[@liyaqathali2648]

Nowadays even 10th class paas person calls himself Entrepreneur or builder or engineer.

[@bhavanishankar8193]

Good afternoon sir I have a doubt ....now we r provided or not extra bars in cantilever beam ...it is enough for top and bottom bars ...?

[@panajotismarioselia1878]

Hello, im just a student so im sorry if my comment dosnt make sence. I remember, that we were told, that if the beam is to high we should add a rebar in the middle it relates to capacity of main diagonal (sorry not sure whats the right transcription)

[@dansuciu88]

that is correct. in EC2 if the beam height is above 700mm you provide additional "side" reinforcement. this is both for constructive purposes and to take torsion

[@emanuellallawmkima3750]

@@dansuciu88 if that is the case... is two rods a necessity?? Or just one on the side is enough

[@dansuciu88]

@@emanuellallawmkima3750 it depends on the beam height. If it is above 700mm, but less than 1000mm you just need 2 constructive bars (1 on each lateral face) tied by a tie or stirrup. If it's above and there is no significant torsion, you place these constructive bars 400mm apart. So more than 1 per face can occur. (have not seen more than 2 in my practice)

[@louiszadupreez]

The additional bars will help with controlling the cracks that develop during loading

[@isaacsitwala2280]

Am enjoying the video clips..keep it up...

[@sj6115]

Development length at free end?

[@mohammedzeaulhoque3888]

Thank you so much to give a very important advice

[@md.mizanurrahmanaru3128]

Nice job Sir,,,, Love u sir,,,,, from Bangladesh

[@topnewsandfun]

Why the stirrups use 8 mm dia rod? Why not 10 mm diameter

[@shalzmv1]

Joints in the cantilever beam should have been in the lower part as the upper part is under tension

[@cttavdiwala3536]

hello sir where r you from

[@aliqadri4672]

0:34 what you say after dual...?

[@beingself5333]

He says provide dowel bars, not dual.

[@sunilkhandagale9966]

Its very imported info abt the pleanth,thanks sir

[@shamigarkongahapitiya5229]

Thank you dear Sri .

[@jharrelmadarang7890]

You should also check the bend of those stirrups. Jeezz

[@sshivan.v7188]

Sir everytime your videos, people always doing 90 degree instead of 135🤣

[@JohnRobertBiate]

Very helpful 👍👍

[@muiizuddin]

You should have guided the Mason earlier!! :-P

[@bresendamarak7205]

Correct it...

[@vuitehruaipuia6665]

135 degrees hooks missing

[@Apnaghar9113]

At junction torsion and shear both developed

[@marksaballa2286]

The spacing of stirrups is a mistake. How can that be the spacing is uniformed?

[@raviakash2955]

You can see that the stirrups are closely spaced near the fixed end.the fixed end is the region where the shear force will be max in a cantilever beam. We provide stirrups to resist shear force and so the region near the fixed supports have closely spaced stirrups. But on the other hand the free end of the cantilever has relatively low or even negligible shear stree. So it is unnecessary and uneconomical to provide more stirrups at the free end. I hope you get it. Thanks

[@tariqhameed5207]

Maran pakhto waya kana Daumra mushkil sara eng de wailo Negative steel ba warkare we practically

[@Yemmmysmog]

Thanks so much, it is helpful

[@MasterCivilEngineering]

Really big mistakes😕😕😕

[@basitali5277]

Sir G der khkaouli move mnga taos shan' teacher pakr dy really Sir

[@john-vt7nk]

Correct..very nice

[@jjgibson3409]

The side steel rods help with weak axis moment

[@louiszadupreez]

Wont the top flange of the beam provide lateral stability? so the beam wont really experience a moment about the weak axis, so the steel in the midsection will be redundent.

[@jjgibson3409]

Hard to say without knowing the loads/design. The side bars can also helps with temperature and shrinkage.

[@albertfoo1569]

Minimally, mostly for cracking purposes if > 750 mm, or if beam designed for torsion

[@exzar9684]

@@louiszadupreezwell designer probably used staad where slabs aren't modelled as part of the analytical model so cantilever ends up with side face reinforcements for torsion which is conservative designwise

[@hussainkazmi4829]

Wastage of steel rods. Wait man. It would be answered by person who designed this structure. You are just a site engineer and your work is to make sure to implement the structural drawing

[@mukundkrishna5161]

Exactly. Dude is going on passing comments like he has designed the structure. He doesn't even look at the drawings, what the structural engineer has provided. Because of guys like him, many of the beginners think whatever he is saying is right.

[@hussainkazmi4829]

@@mukundkrishna5161 exactly. I've come across so many videos where these people are sounding like they are some sort of authorities. You would find site engineers without any clue about how to do structural design manually or by using software. These guys just follow right hand rules( past practices).

[@Dear_9000]

Plot twist: He designed the cantiliver beam and the steelmen just followed the design... Hahahaha

[@godfreymwashi426]

Interesting points

[@1ali1996]

mmmm am nervous about this ....

[@basitali5277]

Sir l have questions sir g mnaga da wale free predou I'm waiting for u sir g plz

[@saadmughal7203]

90% construction in pakistan is faulty. May God help us!

[@lenxi9880]

Klaro Bien bweno bravo 👏

[@muktharshaik1796]

jazakallahu Khair bhai 💖

[@manishkumarjha3427]

Stirrup hooking is incorrect

[@ronieoroceo7903]

Even not cantilever it's always have extra bar,

[@handcannon9814]

I think u need an ipad to sketch on site or just a pen and paper

[@anoopnarayan543]

Anchorage at free end? Please read some good text books!

[@devarushidevarushi1810]

Very good sir

[@sadeghicivil3803]

Wow perfect 👌🏼👌🏼👌🏼

[@kallasai6537]

Guys I had a doubt he said development length is to be in provided in the end . If it's not provided what will happen? What are thay causes also?

[@benjaminsangcaan4980]

Top bar what it should be. 1st of all you havent show drawing if mistake or not

[@sheikhjunid5817]

assalamu alaikum canteen your bheem ke bare mein Bata rahe aap Hindi mein bataiye main Javed thekedar Maharashtra amravati se

[@amsterdamn9236]

At this video he knew, his project is failure

[@animadolai8214]

Thanks

[@peterengti2427]

Thanks🙏 sir

[@fashdbash]

thanks for this

[@cttavdiwala3536]

I want a job in your country

[@cttavdiwala3536]

please reply

[@rajumugali9909]

Nice Sir

[@trailerhow]

Nice

[@victorkirui3998]

Helpful

[@mohanpm8886]

Main beam is correct

[@brendanquinn6894]

If this is true, why didnt you interview the engineer who designed it and hear what he has to say ?

[@popularfunny1583]

Hindi 💪💪💪💪

[@stszubarehasan6844]

বাংলা প্লিজ

[@faizanshaikh6036]

Ur no sir please

[@hamidafridi98]

1st