What I liked most about this video is that it didn't get too abstract or mathematical/numerical. I think you would loose a lot of interest if you deviate from the general concepts. Stirrups and "what they are really for" is fascinating for the curious viewer. I don't want to get lost on the path and exact trajectory of a crack. I'm actually also using this information now for an appraisal of a house I had built in an earthquake-prone area of Turkey over two decades ago, so this comes exactly at the right time. This video, like many of your others, is perfectly balanced. When I, as a layman, explain what I have learned here to a qualified engineer and he raises his eyebrows in astonishment and enlightenment (yes, this really happened) then I know you have done an excellent job 🙂. Thanks for the inspiration!
@@TheEngineeringHub İt's more than well deserved. And I forgot to mention the quality of the graphics, absolutely top-notch in my opinion, they make things so much easier to grasp. I can't imagine the amount of time invested to get these right.
Being a civil engineer, and more specifically a bridge engineer, I have never come across a better explanation than this as to why engineers use stirrups in design. Theory in textbooks, lecturers in university, senior engineers as mentors post university, and none have explained it as clear as you have. Definitely got yourself a new subscriber! Well done on a great video!
@@FPLijahthe process is a bit time consuming but comments like yours make it worth it. I'd say between 50-100 hours of work which is the main reason why we post about once a month. It gets a bit too much with a full-time job as well.
Students of nowadays will find it much easier to grasp complex concepts with audiovisuals like these than during my Civil Engineering undergraduate years just 20years ago. Our lecturers and most text books just makes the topics abstract and unrelated so therefore incomprehensible to most students. Now learning is fun like never before. Keep this up please!
I couldn't agree more as I tried to learn structural engineering... I came to this video as I was reading the school book and found it to be just....but finding this video was very helpful indeed, as well your video demonstration on stress, etc...
I’m not an engineer but I work as a roadway inspector and a lot of my work is on construction of new bridges. We make sure the bridge is built according to plans and specifications. If something minor or large is changed we have to go thru the licensed engineer on site. These videos help me understand the details of bridge plans. Well done!
That's amazing, thanks Joshua. In engineering and construction, small details could make a significant impact on the load-carrying capacity of the structure. Often, this is not too obvious and people may tend to ignore small changes but for example, installing fewer stirrups at the end of a beam could have disastrous effects. Thanks for the discussion, cheers!
I wish there were videos like this back when I was a student. You've done an exceptional job explaining the necessity of stirrups - both verbally and visually.
@@nolesy34 A pedagogue is someone who is good at pedagogy, that is, teaching. I see that it can sometimes be seen as a teacher who is "too strict" - in my case, it is meant purely as a complement. NOT pedophile. So now you've learnt a new word!
One of the best descriptions I have ever seen of basic reinforced concrete engineering. Particularly for non engineers like me. Anyone in building and construction As well as civil construction would benefit from understanding these things. Keep it up.
In addition to this, stirrups also provide ductility. This is really important for strengt and design. Not only shear force resistance but also ductility
one of the best technical video....nobody so far had made me understand the functioning of stirrups understand so good....thanks for the beautiful explanation
My friend that is brilliant work from your side.... i usually watch engineering videos and this recommendation came right off.... i had watched only half way through before i paused and Subscribed... brilliant..
Mate, thank you very much for making such a good, informative videos. I wish University professors do such simple, yet brilliant approach to explaining. You're awesome.
Great video. Maybe you could add another one explaining the differences between pre-stress and post-stress reinforcement, and an example of why an engineer would choose one over the other in real-world application. Basically which to use and why. Thanks for the video! The cross section of normal vs. shear stress really provides a great visual understanding of how they differ and the result of each force on a beam.
@@davidrn2473 Pre-stressed beams generally have both cables and rebar. But yes, the cables are stressed within the casting form and then concrete is poured and allowed to cure. After the form has been stripped and the cables cut from their stressing anchors the beam can take on a significant bend.
Yes, that is exactly the reason. Stirrups resist the shearing forces that are usually the highest near the supports. Most beams do not need stirrups near the mid-span due to the low shearing forces that can be resisted by the concrete alone. When it comes to columns, the shear forces are actually constant along the length of the column. However, the ends are exposed to higher bending moments. The closely spaced ties in columns are usually installed to provided additional ductility and prevent spalling of the concrete in the case of an earthquake.
I hadn’t met such Video or explanation b4 Even when i was teaching de course of principal stresses on Investigating de principal stresses Nd max shear stress i saw these principal stress pictures but it wasn’t have a sufficient explanation even I asked my self the question which is “ if de crack causes by shear force Nd de shear force acts perpendicular on de Cs why de crack propagates I really love it ❤
Good content! I have a little story about concrete bridge spans (I'm not an engineer, so if I label something incorrectly, that is why). I never realized that concrete bridges flex downward (so much) when under load... (Story) I had completed my weekend National Guard drill in El Paso and was on my way back eastward. I still had my uniform on and I decided to pull over and find an obscured place to change into my civilian clothes. I stopped at a dry creek with a bridge across about 10 feet...I went under the bridge and did my thing...I could certainly hear the vehicles crossing overhead and for some reason I put my hand on the underside of the bridge when some vehicles crossed...I could actually feel the span of concrete flexing downward every time a vehicle crossed. Realize that this was a high speed highway (75mph). I understood that there should be some measure of flex, but I never realized it was to this degree. Of course, while driving, you never really notice the dipping action of such a bridge.
Thanks for the interesting story Glenn! It is fascinating how flexible these structures can be. The flexibility is especially pronounced because they tend to be much slender than buildings (long but not as thick). Bridge deflections are usually limited by code to a value between 1/800 to 1/1000 of the span (depending on type, use, material etc). This means that a span of 30m (100ft) can (allowably) deflect up to 300mm (1ft) which can be scary to observe. This may get further increased if the bridge is not properly maintained and has cracked or deteriorated concrete i.e. loss of stiffness.
Good video! It may take a while before one goes viral, but when that happens people will watch all your old videos too. It's nice to see diagrams designed specifically for this topic instead of stock footage.
Thank you so much Nathan! We spend a lot of time designing diagrams that can communicate the message as clearly as possible. We haven't had huge success yet but we will just keep working and hoping to reach as many people as possible. Cheers
as a viewer, these types of videos always bring gratitude to the creators. there are tons of videos for technology, and architecture-related courses. perhaps civil engineering has less amount of interesting videos compared to others. it's an engaging video with theoretical explanations of real-life situations. wish to see more civil engineering and construction-related video from you
Hi Division by Zero, thanks for the nice comment!. More videos are on the way. In meanwhile, we encourage you to check out some of our older content. Cheers!
Thank you for putting so much time and effort into making this video which has lucid explanation. That's how so many complex concepts becomes a peace of cake. A great video showing textbook diagrams in practical scenario. Thank you for saving my time. Love from India. ❤
@@TheEngineeringHub Yup. I started exploring your channel and found so many videos like this one. May I suggest a few topics in due time so that you can explain them like this ?
Dude, you did a really great job explaining this important yet neglected concept (specially in undergrad level). Really appreciate the video! Excellent breakdown.
Congrats on creating I Love Engineering! This is such an amazing initiative, helping bring engineering closer to the public. As an engineer myself, I can totally relate to this and appreciate the effort that goes into engineering projects. The videos, resources and content make it all the more enjoyable to learn and explore engineering. Whether you are just starting out or just simply interested, I Love Engineering will help open your eyes to the limitless possibilities of what is achievable in this field. Keep up the excellent work!
Thanks for the information in this vido and in others.. Just a note - minute 6: even upon considerable crack opening, the compression zone contribution to the shear resistance is minimal. Even though a compressive stress increases the shear strength, equilibrium does not throw much shearing stresses to the compression zone.
I think this is the best visuals of showing the various forces, and why they occur. Way better than I got at uni (though that was nearly 30 years ago). And I subscribed.
Good Video. You forgot to mention couple of other functions of stirrups, f.e.: In columns - holding together compressed reinforcement, especially during fire (buckling) -improvement of the anchorage conditions -Increase steel and concrete cooperation as a whole
Excellent and clear explanation of this important and commonly misunderstood failure mode. They also act to confine concrete against bursting in columns. You might want to look at your annotation at 8.19. Best wishes.
That is very important concept. I would always wish that to understand from my teacher but he would have not abled to satisfy me. But I watched this video 4 to 5 times and I feel very confident.
Well presented, thanks! I would have added a reference to concrete beams in the title for the "non engineers". Anyone who's involved in construction would do well to watch this.
Hi dogmatix! Many have migrated in that direction, as a structural engineer myself, I think it's an amazing field. If you enjoy the videos on this channel, chances are you will also enjoy structural engineering.
I'm retired and living in a third world county (Mexico) where as the over whelming vast majority of homes have concret roofs. In the past prior to the advent of using rebar, The various rooms within a home had to be a certain size or the span of concret aka roof above would fall in. Which was most generally in those days the equalivent of two inchs. Today using rebar a 1/4 in in diameter, if and when sufficent rebar is implemented, a roof can span a larger area, thus the sizes of room beneath it are now larger. If and when one thinks ahead and there are plans someday to adding an additional room or rooms above the original. If and when the first level has no rebar or only a 1/4 of inch rebar. The floor above which is the roof below. Will agian fall in. Thus the one who buys a house when it was built using no or 1/4 in rebar and isn't aware of it when they personall elect to increase the size of their home to include a second livng area above the first. Have issues with the roof aka floor above, falling in on them. But by then as allways in Mexico. Once purchased, it's the owner issues. Not the contractors. I should add that there are repitable constuction contract who build homes. But the cost of them doing it vs someone who's agenda is to just build one as cheap as they can and make the same money as the more expensive contractor. Will sell for nearly 25 percent less. Which allows them to build more houses because who wants to pay 25% more for what appears to be the same house. In the U.S.A. what is referred to as town houses or quad homes; And not houses. Are built with one wall between two adjoining homes just like apartment complex's do. In Mexico and assumable other third world countries. The homes built adjoining others some times twenty in a row. Though there is only one wall that separates one from the one adjoining. They are still referred to as houses.
As a former cement guy who tied more than his fair share of steel back in the day, I always thought the verticals were to hold the horizontals in place while the concrete was being placed.
the stirrups delivered on my job were too long and would have no cover if installed vertically and we had no time to reorder, so we laid them over across the potential cracks and achieved our cover. we probably added some extra, just to make sure, they supplied too many! we conferred with the design engineer and he was happy with our solution, concrete poured on time.
Hi Stephen! That's an excellent, and in fact, the optimal solution. I would also imagine it took longer to install them at an inclined position compared to installing them vertically (if the length was correct)? The additional man-hours is probably the main reason why this is rarely done in practice. In reality, this is the best material utilization.
@@TheEngineeringHub Steel fixers supply and install problem, I just saved my own concrete pour deadline. I am a construction civil engineer, not a design engineer, no insurance for that and so insisted on the design inspection. 😉. Hahaha. He was pleased with the solution. I mentioned it here because others may find it useful. The ligatures must lean the right way, not parallel to the cracking. Hahaha.
@@stephenbrickwood1602 We are in fact design engineers so it was very interesting to hear from someone that spends more time in the field and less time in the office like us. And yes the inclination angle is absolutely crucial, otherwise, it goes from most optimal to useless if they are installed parallel to the crack. Cheers and thanks for the discussion!
Terrific video. Thanks. If you added the graphs of Normal Forces + Sheer you would get almost the exact shape of the crack. the bottom (blue) normal graph line mostly cancels out the lower half of the Stress curve, but past the mid point they add resulting in an almost horizontal line. I know that what I've just learned in your video I'll now be able to spot in real examples, and I'll be able to build better structures. This is also exactly the type of information Elon Musk calls 'First Principles'.
You can place the stirrups at a 45 degree angle for a more material efficient design with more spacing between them and less use of Steel. Great video btw!
Oh, as soon as people start thinking of ways to save on material - use less steel, lower costs - I start to get nervous. Don't come up with too many of those ideas, please!
That is most comprehensive video on this topic, we need similar video on column footing, also choice of shear and moment connection? We also need to know the action of masonry or wall under loads if you can.
Geez, I've only dabbled in structural, but aren't you forgetting to mention beam internal shear? The addition of the vertical sheer vector with the internal (horizontal) sheer vector is why the crack forms as a diagnol. BTW, mom always said the internal shear is greatest at the ends of the beam, and zero at the midpoint or point load.
I think you missed an important concept of stirrups providing concrete confinement. The confinement of the concrete within the rebar and stirrups helps to maintain the geometric spacing of the original reinforcement design. This is a very important concept especially for high seismic zones. See the lessons learned from the California Northridge earthquake. Search for the report: f0016653-final-report-task-2175.pdf By the way, American concrete codes for structures intended for human use provide additional margins of safety for life-saving. In an earthquake, we're not so much interested in avoiding damage or overload of a beam or structure as we are trying to ensure there is enough strength in failure that a structure does not pancake.
Confinement is absolutely crucial for columns but actually not as crucial for beams (assuming no torsion) which is what this video is mostly focused on. In fact, often stirrups in beams are U-shaped rather than the hoops used in column design. Rather than that, we agree completely with you, William. We would also add the importance of the "Strong column, weak beam philosophy" which is crucial for ensuring that the beams fail first and dissipate energy. This way pancaking of the slabs could be avoided. Cheers, thanks for the discussion!
This is for simply supported beams not moment connection or continuous beams . Shear is at 45° to vertical off simple supported ends at 1.5× reaction at support. Also pre stressed and post tension very different also .
Veey well spotted. The Mohr-Coloumb criterion described in the soil video also applies to concrete! In essence, it governs the failure of brittle materials
As a side note, if someone is certified as a structural engineer and considers themselves to be a qualified engineer I think they should be concerned with the energy efficiency of the building as part of the overall integrity of the structure. That is now mandated if I'm not mistaken. 🤔
I was looking through the catalog of videos on this channel. It is interesting, and somewhat disheartening, that the videos with arguably more clickbaity titles get more views then the ones with straight forward ones.
A company I once worked for was expanding, and bought an abandoned property and company that once produced pre-stressed concrete beams used in bridge and building construction. All their equipment and machinery was still in place when the business closed its doors. It was quite interesting to see how their beams were being made. The forms were built per engineered specs. When ready for pouring of the concrete, very heavy steel wire rope cables were layed full length into the forms and attached at each end to stretcher winch's, which would pull the cables to the point of elongation. Once the poured concrete in the forms cured, the cable's were cut free from the tension winch's, leaving the beam in permanent lengthwise compression. These beams were so strong and effective in heavy construction, they were specified all over the country. I believe the company's name was Rackle, located in Garfield Heights, Ohio. I believe they closed up shop around 1968. Thanks for the interesting video.
Awesome video! I learned things about shear vs. normal stress today. When we make our precast columns where I work, we have stirrups around the bars that run the length of the column, (typically three #8's on opposing sides where the corbels are or three #8's on each face depending on what the calculator says) along with stirrups that go through the center of the column and tie the bars that are in the middle of each face together. Being that this is a vertical element, the purpose of these bars is partially what you described in this video with shear, and partially to keep the rebar from deforming outward, away from the center of the column. We also have a beam element that had a cross section like an upside down fat letter "T". I've seen both stirrups and mesh used in these elements, but in all cases there's several (between 24 and 36) 1/2" diameter cables pulled to around 30,000 pounds each. It's really fun to see the beams jump up when they release the strands from the form!
One could start to wonder why we put concrete anywhere where it will be under tension. Its function there appears to be little more than holding the rebar in place, and protecting it from corrosion.
You are not wrong Sylvia. The reasons are probably more practical than technical. Building forms in a rectangular shape is much more cost effective. For some other places, like an internal column that could bend in any direction, the tension forces just can't be avoided. Thanks for the insightful comment, cheers!
What I liked most about this video is that it didn't get too abstract or mathematical/numerical. I think you would loose a lot of interest if you deviate from the general concepts.
Stirrups and "what they are really for" is fascinating for the curious viewer. I don't want to get lost on the path and exact trajectory of a crack.
I'm actually also using this information now for an appraisal of a house I had built in an earthquake-prone area of Turkey over two decades ago, so this comes exactly at the right time.
This video, like many of your others, is perfectly balanced. When I, as a layman, explain what I have learned here to a qualified engineer and he raises his eyebrows in astonishment and enlightenment (yes, this really happened) then I know you have done an excellent job 🙂. Thanks for the inspiration!
Comments like this is what makes it all worth it! Thank you!🙏
@@TheEngineeringHub İt's more than well deserved. And I forgot to mention the quality of the graphics, absolutely top-notch in my opinion, they make things so much easier to grasp. I can't imagine the amount of time invested to get these right.
Was this comment before or after the earthquake?
Agree 100%! Nothing makes me change videos faster like seeing lots of math and calculations
Being a civil engineer, and more specifically a bridge engineer, I have never come across a better explanation than this as to why engineers use stirrups in design. Theory in textbooks, lecturers in university, senior engineers as mentors post university, and none have explained it as clear as you have. Definitely got yourself a new subscriber! Well done on a great video!
Wow, so flattering to hear!! Thank you so much, FPLijah!
@@TheEngineeringHub It was a suggested video, and so glad I stumbled across it🙌🏼 Can't imagine how long it takes to make a video like this
@@FPLijahthe process is a bit time consuming but comments like yours make it worth it. I'd say between 50-100 hours of work which is the main reason why we post about once a month. It gets a bit too much with a full-time job as well.
@@TheEngineeringHub wow! Crazy hours of work! Honestly we appreciate the effort bro🙌🏼🔥
Disliked unsubbed
Students of nowadays will find it much easier to grasp complex concepts with audiovisuals like these than during my Civil Engineering undergraduate years just 20years ago. Our lecturers and most text books just makes the topics abstract and unrelated so therefore incomprehensible to most students. Now learning is fun like never before. Keep this up please!
I agree.
I couldn't agree more as I tried to learn structural engineering...
I came to this video as I was reading the school book and found it to be just....but finding this video was very helpful indeed, as well your video demonstration on stress, etc...
I’m not an engineer but I work as a roadway inspector and a lot of my work is on construction of new bridges. We make sure the bridge is built according to plans and specifications. If something minor or large is changed we have to go thru the licensed engineer on site. These videos help me understand the details of bridge plans. Well done!
That's amazing, thanks Joshua. In engineering and construction, small details could make a significant impact on the load-carrying capacity of the structure. Often, this is not too obvious and people may tend to ignore small changes but for example, installing fewer stirrups at the end of a beam could have disastrous effects. Thanks for the discussion, cheers!
Aviation works in a similar way. A DER does the design, a DAR makes sure that it's built that way. Both are crucial functions.
@@lautoka63 I’d love to get in the aviation field. Hard nut to crack without any experience or knowing someone in the field to bring you in.
I wish there were videos like this back when I was a student. You've done an exceptional job explaining the necessity of stirrups - both verbally and visually.
Thank you for the nice words, Dushan. Svako dobro, pozdrav!
Which country are you
Extraordinarily clear, easy-to-follow explanation. This guy is a BORN pedagogue.
WHOAH! MAN that's out of line! Do you have proof hes attracted to minors?
@@nolesy34 A pedagogue is someone who is good at pedagogy, that is, teaching. I see that it can sometimes be seen as a teacher who is "too strict" - in my case, it is meant purely as a complement. NOT pedophile. So now you've learnt a new word!
@@blixten2928 oh....
Oooooooh
One of the best descriptions I have ever seen of basic reinforced concrete engineering. Particularly for non engineers like me. Anyone in building and construction As well as civil construction would benefit from understanding these things. Keep it up.
In addition to this, stirrups also provide ductility. This is really important for strengt and design. Not only shear force resistance but also ductility
why is V_dowel ignored?
I agree, stirrups prevent buckling of longitudinal bars in the compression side, letting yielding of bars in the tension side.
Thank you for that interesting video: NO background music, very good explanation. Brilliant!
Very interesting. I've worked in concrete for almost 20 years now. Thank you for this information .
That's awesome JareDevilDog. Glad that you found it interesting, did you also know the reason or was this new? Regards.
@@TheEngineeringHub I didn't realize that was the reason. Your channel is very informative.
i wish my uni lectures were like this, so clear and concise. i'm very impressed, thanks for the video!
one of the best technical video....nobody so far had made me understand the functioning of stirrups understand so good....thanks for the beautiful explanation
Just WOW! Every line of the video is to the point and explains shear very well.
Thank you for the feedback and nice words Raghav, much appreciated!
@@TheEngineeringHub why is V_dowel ignored? care to explain please?
This video is better at teaching than most of the engineering teachers at the engineering university. Thx bro
My friend that is brilliant work from your side.... i usually watch engineering videos and this recommendation came right off.... i had watched only half way through before i paused and Subscribed... brilliant..
Thank you so much chapad, we are very glad to have you as a subscriber. Stay tuned, more videos are on the way!
Nnnnnnnnnnnnnnnnnn
Nnnnnnnnnnnnnnnnnn
Nnnnnnnnnñnnnnnññnn
@@TheEngineeringHub I'm subscribed and turned on the bell
Mate, thank you very much for making such a good, informative videos. I wish University professors do such simple, yet brilliant approach to explaining. You're awesome.
University 100,000 debt
TH-cam videos Free
Fake engineering credentials
Collapsed building
Jail Priceless
Great video. Maybe you could add another one explaining the differences between pre-stress and post-stress reinforcement, and an example of why an engineer would choose one over the other in real-world application. Basically which to use and why. Thanks for the video! The cross section of normal vs. shear stress really provides a great visual understanding of how they differ and the result of each force on a beam.
Great suggestion and thank you so much for the feedback PA Mike, much appreciated!
When you say pre-stress, do you mean pre stressed cables within a beam instead of rebar?
why is V_dowel ignored?
@@davidrn2473 Pre-stressed beams generally have both cables and rebar. But yes, the cables are stressed within the casting form and then concrete is poured and allowed to cure. After the form has been stripped and the cables cut from their stressing anchors the beam can take on a significant bend.
thank you.I have been looking for exactly this explanation of why stirrups are concentrated nearer the ends of beams and some columns
Yes, that is exactly the reason. Stirrups resist the shearing forces that are usually the highest near the supports. Most beams do not need stirrups near the mid-span due to the low shearing forces that can be resisted by the concrete alone.
When it comes to columns, the shear forces are actually constant along the length of the column. However, the ends are exposed to higher bending moments. The closely spaced ties in columns are usually installed to provided additional ductility and prevent spalling of the concrete in the case of an earthquake.
Never thought past the obvious reason for stirrups.
Learn something new every day. Thanks.
Great comments.
Wow great job explaining this. Even showing the principal stresses.
Thanks Neil, hope you enjoyed it!
This is what we call next level of explanation 👌
Thank you Ajmal, your support is very appreciated!
I hadn’t met such Video or explanation b4
Even when i was teaching de course of principal stresses on Investigating de principal stresses Nd max shear stress i saw these principal stress pictures but it wasn’t have a sufficient explanation even I asked my self the question which is “ if de crack causes by shear force Nd de shear force acts perpendicular on de Cs why de crack propagates
I really love it ❤
Thank you Arman 🙏
I will look forward for more of your videos Sir. Your discussion was very systematic and visual. It helped me a lot.
Awesome, thank you!
Good content!
I have a little story about concrete bridge spans (I'm not an engineer, so if I label something incorrectly, that is why). I never realized that concrete bridges flex downward (so much) when under load... (Story) I had completed my weekend National Guard drill in El Paso and was on my way back eastward. I still had my uniform on and I decided to pull over and find an obscured place to change into my civilian clothes. I stopped at a dry creek with a bridge across about 10 feet...I went under the bridge and did my thing...I could certainly hear the vehicles crossing overhead and for some reason I put my hand on the underside of the bridge when some vehicles crossed...I could actually feel the span of concrete flexing downward every time a vehicle crossed. Realize that this was a high speed highway (75mph). I understood that there should be some measure of flex, but I never realized it was to this degree. Of course, while driving, you never really notice the dipping action of such a bridge.
Thanks for the interesting story Glenn! It is fascinating how flexible these structures can be. The flexibility is especially pronounced because they tend to be much slender than buildings (long but not as thick). Bridge deflections are usually limited by code to a value between 1/800 to 1/1000 of the span (depending on type, use, material etc). This means that a span of 30m (100ft) can (allowably) deflect up to 300mm (1ft) which can be scary to observe. This may get further increased if the bridge is not properly maintained and has cracked or deteriorated concrete i.e. loss of stiffness.
Good video! It may take a while before one goes viral, but when that happens people will watch all your old videos too. It's nice to see diagrams designed specifically for this topic instead of stock footage.
Thank you so much Nathan! We spend a lot of time designing diagrams that can communicate the message as clearly as possible. We haven't had huge success yet but we will just keep working and hoping to reach as many people as possible. Cheers
It is viral now
The work and dedication that went into these videos really shows.
I've an interview coming and couldn't asked for any better time to come across such a channel. keep up the good ma man.
as a viewer, these types of videos always bring gratitude to the creators. there are tons of videos for technology, and architecture-related courses. perhaps civil engineering has less amount of interesting videos compared to others. it's an engaging video with theoretical explanations of real-life situations. wish to see more civil engineering and construction-related video from you
Hi Division by Zero, thanks for the nice comment!. More videos are on the way. In meanwhile, we encourage you to check out some of our older content. Cheers!
Thank you for putting so much time and effort into making this video which has lucid explanation.
That's how so many complex concepts becomes a peace of cake.
A great video showing textbook diagrams in practical scenario.
Thank you for saving my time.
Love from India. ❤
Thanks Deepak, we are so glad you found the video useful. Stay tuned for more intuitive explanations of engineering topics. Cheers!
@@TheEngineeringHub Yup. I started exploring your channel and found so many videos like this one.
May I suggest a few topics in due time so that you can explain them like this ?
@Deepak-pi9xx Yes, please! New suggestions are always welcomed
As a student in the field of engineering this explanation is most important.
What a lovely video and calm voice! The explanations are wonderful and a real treat.
And the graphics,… I mean WOW!
This video communicates the concepts so well. The animations are great.
Thank you again Prando
I’ll have to bookmark this.
Very informative!
Dude, you did a really great job explaining this important yet neglected concept (specially in undergrad level). Really appreciate the video! Excellent breakdown.
Thanks for the compliments S O, really glad you enjoyed it!
Congrats on creating I Love Engineering! This is such an amazing initiative, helping bring engineering closer to the public. As an engineer myself, I can totally relate to this and appreciate the effort that goes into engineering projects. The videos, resources and content make it all the more enjoyable to learn and explore engineering. Whether you are just starting out or just simply interested, I Love Engineering will help open your eyes to the limitless possibilities of what is achievable in this field. Keep up the excellent work!
Incredible work! I really loved the visualizations!
Best regards from Germany 🙋♀️
JA JA
Thanks for the information in this vido and in others.. Just a note - minute 6: even upon considerable crack opening, the compression zone contribution to the shear resistance is minimal. Even though a compressive stress increases the shear strength, equilibrium does not throw much shearing stresses to the compression zone.
I think this is the best visuals of showing the various forces, and why they occur. Way better than I got at uni (though that was nearly 30 years ago). And I subscribed.
I needed this while in school.
Excellent video, I was so excited to like before finishing it hope you make more!
Good Video. You forgot to mention couple of other functions of stirrups, f.e.:
In columns - holding together compressed reinforcement, especially during fire (buckling)
-improvement of the anchorage conditions
-Increase steel and concrete cooperation as a whole
Excellent and clear explanation of this important and commonly misunderstood failure mode. They also act to confine concrete against bursting in columns. You might want to look at your annotation at 8.19. Best wishes.
Thank you for the informative video. It will definitely helps for the upcoming midterm. Cheers mate
Good luck with your midterms British, but don't forget to also study and not just watch TH-cam videos 😄
Wow, this was fantastic, thank you! I had no idea so much was involved, or how they calculated what stirrups to put where.
That is very important concept. I would always wish that to understand from my teacher but he would have not abled to satisfy me. But I watched this video 4 to 5 times and I feel very confident.
Very informative and conceptual video.
I liked it very much.
Pls keep uploading such animated videos as it clears many doubts RCC and SOM
Doubts of RCC and SOM*
Thank you Prashant, more videos are on the way, stay tuned! In meanwhile, feel free to check out some of our older videos, cheers!
Gonna have to subscribe. My job consists of me bidding for rebar on projects. So understanding how things are done in the field is always useful.
Nice video. I want more.
Ooo I like this how steel and concrete works. Also the psi in concrete plays great role in structural design.
These videos are highly recommended.
thank you very much for your effort you have given us many information about concrete and stirrups.
Our pleasure!
Thankyou this is really what i called an explanation with example & simplicity.
Well presented, thanks! I would have added a reference to concrete beams in the title for the "non engineers". Anyone who's involved in construction would do well to watch this.
Loved this.
I’m a carpenter, thinking about a career change to a structural engineer. Thanks for these videos.
Hi dogmatix! Many have migrated in that direction, as a structural engineer myself, I think it's an amazing field. If you enjoy the videos on this channel, chances are you will also enjoy structural engineering.
@@TheEngineeringHub thanks for the positive reinforcement! I thoroughly appreciate that! 🙂
Excellent content
I'm retired and living in a third world county (Mexico) where as the over whelming vast majority of homes have concret roofs. In the past prior to the advent of using rebar, The various rooms within a home had to be a certain size or the span of concret aka roof above would fall in. Which was most generally in those days the equalivent of two inchs. Today using rebar a 1/4 in in diameter, if and when sufficent rebar is implemented, a roof can span a larger area, thus the sizes of room beneath it are now larger. If and when one thinks ahead and there are plans someday to adding an additional room or rooms above the original. If and when the first level has no rebar or only a 1/4 of inch rebar. The floor above which is the roof below. Will agian fall in. Thus the one who buys a house when it was built using no or 1/4 in rebar and isn't aware of it when they personall elect to increase the size of their home to include a second livng area above the first. Have issues with the roof aka floor above, falling in on them. But by then as allways in Mexico. Once purchased, it's the owner issues. Not the contractors.
I should add that there are repitable constuction contract who build homes. But the cost of them doing it vs someone who's agenda is to just build one as cheap as they can and make the same money as the more expensive contractor. Will sell for nearly 25 percent less. Which allows them to build more houses because who wants to pay 25% more for what appears to be the same house.
In the U.S.A. what is referred to as town houses or quad homes; And not houses. Are built with one wall between two adjoining homes just like apartment complex's do. In Mexico and assumable other third world countries. The homes built adjoining others some times twenty in a row. Though there is only one wall that separates one from the one adjoining. They are still referred to as houses.
Thats yhe best video on shear force and principal stresses on the internet
This was absolutely brilliant and very helpful, thank you so much! I'm so glad TH-cam recommended a video from this channel
Thanks for sharing the concept very clearly.
Really appreciate to make such a civil engineering related video in further.
Thanks again.
Thanks. Watching this video has been a very educational journey.
Thank you for the name of the further research topics. I will look up stress transformations as a refresher for sure
As a former cement guy who tied more than his fair share of steel back in the day, I always thought the verticals were to hold the horizontals in place while the concrete was being placed.
Hats off man....subscribed to this worthy channel
Much appreciated Arun, stay tuned for more!
the stirrups delivered on my job were too long and would have no cover if installed vertically and we had no time to reorder, so we laid them over across the potential cracks and achieved our cover.
we probably added some extra, just to make sure, they supplied too many!
we conferred with the design engineer and he was happy with our solution, concrete poured on time.
Hi Stephen! That's an excellent, and in fact, the optimal solution. I would also imagine it took longer to install them at an inclined position compared to installing them vertically (if the length was correct)? The additional man-hours is probably the main reason why this is rarely done in practice. In reality, this is the best material utilization.
@@TheEngineeringHub Steel fixers supply and install problem, I just saved my own concrete pour deadline.
I am a construction civil engineer, not a design engineer, no insurance for that and so insisted on the design inspection. 😉. Hahaha.
He was pleased with the solution.
I mentioned it here because others may find it useful.
The ligatures must lean the right way, not parallel to the cracking. Hahaha.
@@stephenbrickwood1602 We are in fact design engineers so it was very interesting to hear from someone that spends more time in the field and less time in the office like us. And yes the inclination angle is absolutely crucial, otherwise, it goes from most optimal to useless if they are installed parallel to the crack. Cheers and thanks for the discussion!
Terrific video. Thanks. If you added the graphs of Normal Forces + Sheer you would get almost the exact shape of the crack. the bottom (blue) normal graph line mostly cancels out the lower half of the Stress curve, but past the mid point they add resulting in an almost horizontal line. I know that what I've just learned in your video I'll now be able to spot in real examples, and I'll be able to build better structures. This is also exactly the type of information Elon Musk calls 'First Principles'.
Great video: clear and concise!
Thank you Michele, we are glad you found it informative!
Good info. Quite worth a reader with good speach!
Definitely got my attention. Precise and well explained. Subscribed!
Thank you 🙏
I was having a huge problem with understanding how those stirrups are working... Man thanks to you for help) btw hello from Russia)
You can place the stirrups at a 45 degree angle for a more material efficient design with more spacing between them and less use of Steel. Great video btw!
Oh, as soon as people start thinking of ways to save on material - use less steel, lower costs - I start to get nervous. Don't come up with too many of those ideas, please!
That is most comprehensive video on this topic, we need similar video on column footing, also choice of shear and moment connection? We also need to know the action of masonry or wall under loads if you can.
This is a _damn_ good explanation.
This is extremely well produced and informative, thank you for your high quality work!
Thank you Neuro for taking a second to give us feedback. We appreciate you!
Very well done! I am grateful for your efforts.
introduction ! man that was brillliant , great job
Thank you Bilel!
Geez, I've only dabbled in structural, but aren't you forgetting to mention beam internal shear? The addition of the vertical sheer vector with the internal (horizontal) sheer vector is why the crack forms as a diagnol. BTW, mom always said the internal shear is greatest at the ends of the beam, and zero at the midpoint or point load.
Feeding the TH-cam algorithm. Great video. We appreciate it.
Very well explained, very educational.
Thank you Cesar!
This is absolutely brilliant so glad I found this channel🙏
That is brilliant man, being a teacher i really appriciate your efforts, n subscribed your channel
Thank you so much Muhammad. Your support is very much appreciated!
Amazing! ❤
This is top notch explanation 👌
Could you please discuss alternative concrete reinforcement, such as fiberglass, basalt, stainless steel micro, bamboo, etc.
I think you missed an important concept of stirrups providing concrete confinement. The confinement of the concrete within the rebar and stirrups helps to maintain the geometric spacing of the original reinforcement design. This is a very important concept especially for high seismic zones. See the lessons learned from the California Northridge earthquake. Search for the report: f0016653-final-report-task-2175.pdf By the way, American concrete codes for structures intended for human use provide additional margins of safety for life-saving. In an earthquake, we're not so much interested in avoiding damage or overload of a beam or structure as we are trying to ensure there is enough strength in failure that a structure does not pancake.
Confinement is absolutely crucial for columns but actually not as crucial for beams (assuming no torsion) which is what this video is mostly focused on. In fact, often stirrups in beams are U-shaped rather than the hoops used in column design. Rather than that, we agree completely with you, William. We would also add the importance of the "Strong column, weak beam philosophy" which is crucial for ensuring that the beams fail first and dissipate energy. This way pancaking of the slabs could be avoided. Cheers, thanks for the discussion!
Excellent explanation. One of the best.
This is for simply supported beams not moment connection or continuous beams .
Shear is at 45° to vertical off simple supported ends at 1.5× reaction at support.
Also pre stressed and post tension very different also .
Such a great informative channel
Brilliant Job brother. 🙏✔️👌
Boss tnx for sharing the beams and concrete tnx again god bless you and your family
Our pleasure!
Extra ordinary work.
6:29 That looks like an inverted version of the "soil shear curve" from your other videos.
Veey well spotted. The Mohr-Coloumb criterion described in the soil video also applies to concrete! In essence, it governs the failure of brittle materials
@@TheEngineeringHub :)
I was thinking that concrete (being made of sand and aggregate), is basically "really tightly bound soil".
As a side note, if someone is certified as a structural engineer and considers themselves to be a qualified engineer I think they should be concerned with the energy efficiency of the building as part of the overall integrity of the structure. That is now mandated if I'm not mistaken. 🤔
Great explanation and great effort you have sir. Make video on bond stress , lap length and development length.
Well explained along with great visuals. Love this.
Excellent mate. Thanks for summing it up for me.
I was looking through the catalog of videos on this channel. It is interesting, and somewhat disheartening, that the videos with arguably more clickbaity titles get more views then the ones with straight forward ones.
Great job .
Thank you sir!
Very good explanation. So helpful and interesting.
Glad you liked it
A company I once worked for was expanding, and bought an abandoned property and company that once produced pre-stressed concrete beams used in bridge and building construction. All their equipment and machinery was still in place when the business closed its doors. It was quite interesting to see how their beams were being made. The forms were built per engineered specs. When ready for pouring of the concrete, very heavy steel wire rope cables were layed full length into the forms and attached at each end to stretcher winch's, which would pull the cables to the point of elongation. Once the poured concrete in the forms cured, the cable's were cut free from the tension winch's, leaving the beam in permanent lengthwise compression. These beams were so strong and effective in heavy construction, they were specified all over the country. I believe the company's name was Rackle, located in Garfield Heights, Ohio. I believe they closed up shop around 1968. Thanks for the interesting video.
Awesome video! I learned things about shear vs. normal stress today.
When we make our precast columns where I work, we have stirrups around the bars that run the length of the column, (typically three #8's on opposing sides where the corbels are or three #8's on each face depending on what the calculator says) along with stirrups that go through the center of the column and tie the bars that are in the middle of each face together. Being that this is a vertical element, the purpose of these bars is partially what you described in this video with shear, and partially to keep the rebar from deforming outward, away from the center of the column.
We also have a beam element that had a cross section like an upside down fat letter "T". I've seen both stirrups and mesh used in these elements, but in all cases there's several (between 24 and 36) 1/2" diameter cables pulled to around 30,000 pounds each. It's really fun to see the beams jump up when they release the strands from the form!
One could start to wonder why we put concrete anywhere where it will be under tension. Its function there appears to be little more than holding the rebar in place, and protecting it from corrosion.
You are not wrong Sylvia. The reasons are probably more practical than technical. Building forms in a rectangular shape is much more cost effective. For some other places, like an internal column that could bend in any direction, the tension forces just can't be avoided. Thanks for the insightful comment, cheers!
In many applications, I think the truss would fit bill much better. Protecting the steel from corrosion can be achieved through paint coating.