Hey Tyler. I’m a reinforcing rod worker apprentice that just recently finished my level one training. We’ve watched most of your videos in class and they really helped us out a lot .
France during that period produced a number of exceptional thinkers and tinkers- Darcy's theories and formulas re how water (fluids) move through various densities of strata is still big when planning both water and oil wells. It was the industrial revolution and it's needs that were really receptive to new ideas. Bravo for shining a little more light on those tinkers and thinkers!FR
@@TylerLey It was a great time for "critical thinkers" - the thresh hold of the Industrial Revolution. In America, Fulton and a host of others changed farming and laid the ground works for the greatest manufacturing boom ever- Henry Ford, the Wright Bros couldn't have happened with all that happened all over the world from about 1750 to 1900. Man's reach would finally be something he could actually see. You are the guy that spent the time and got the degree- and then applied the bejabbers out of it! Me, I'm an over educated plumber, with a jones for the history of my own profession and the ones around it. I can retell stories about others who did big things- you, my friend are very likely to push into something no one ever foresaw! Good Hunting!FR
Thank you for making me a concrete freak too! I will be building a home in the Philippines and I have been studying SRC and many other aspects of civil engineering so I may be certain my home is built strong and safe. I have learned so much from you and your colleagues.
Be sure to study the techniques for making earthquake-safe concrete buildings. They have lots of earthquakes in the Philippines. Take a look at a map of the fault lines under the Philippines. Yikes! Also typhoons and flash floods. Pay attention to the elevation of your site, and to techniques for keeping your roof on in high winds. Maybe Tyler would be kind enough to make a video on planning a concrete building in such a high-risk area.
I love how enthusiastic you are about concrete. This is the wonder of the internet. We can get connected to so many people who are so into their niche which gives us quality content like this.
Brilliant. So many fantastically confounding topics covered in one video, abridged comprehensively . Thank you for your enthusiasm and diligence!!!!!!!!!!
Hahaha! He was a gardener? Excellant. i have been in horticulture 60 years! And concrete work was a big part of our lives in creating things! In College , i even took a 3 day intensive field class of the properties of concrete. In 1980, there was 2 of us women in that class of 25! That 1 weekend class gave me the science of concrete! As a landscaper & now on small ranch- thar knowledge has helped when i bulit my big corral & horse shelters! Love your channel!
This video is a summary of what teachers are trying to tell in lessons of reinforced concrete, but they cannot. Maybe they do, but not make it fun like you! Thanks a lot! I really enjoyed listening you.- Greetings from Turkey
Tyler Ley He said : « I dont know what to say prof ... but you are intelligent and have great knowledge, i would love to attend all your classes... wish you success Tyler »
Thanks for this. As an Engineer, this has made me learn more about concrete and reinforcement. Concrete is strong in compression but weak in tension that's the main reason why reinforcement is required. Doing this will eliminate or reduce cracks to be as minimal as possible. Well explained!👍
The best series of base understanding concrete really easy to understand, therotical and pracrical usefull wery inspirering, thise infos are really neded in the industry.. Thanks a lot.. I have made so many mistakes myself, and payed the price, my mistakes made me look for better ways to do concreate, this is the best so far.
Tyler, I think you’re the only person besides myself that gets giddy about concrete construction. I’m not a DIY home owner...oh wait...I guess I am, I just happen to have a General Engineering and General Building license in California for about 40 years. I’m getting ready to design a, my first, post tension sog in northwest MO. I’m so happy 😁 !
I love you dude! You are such a good teacher! Thank you so much for all your hard work and explaining thing so simply so I can actually understand! God bless you bro!
The ground will heave and contract. I introduce the red clay we have in some parts of north central Texas, NW of DFW about an hour or so. 1+" cracks in the ground in the summer, zero cracks in the wet(ish) months. Slabs on grade can heave and fall at the perimeter and, the clay under the center area will dry out and contract, leaving voids under the concrete if there are sufficient piers to support it or turning the slab into a cereal bowl if there aren't. It's not just the friction of the soil holding the slab from expanding and contracting causing tension horizontally, it's the up and down at the edges as the soil gets wet and dries out and the depression in the center as the clay dries out never to get wet again (covered with concrete).
Another excellent video; well explained. Maybe a demo of a beam cracking with and without reinforcement. Minor point at 08:10 you mention the steel should be 1.5" from the top (67mm) hmm I think it should be (40mm). I only point it out as lot from around the world will see the metric. I see too often builders think the steel mesh should go in the center of the slab for slab on grade/ground. Cheers Pulpo
Pulp! Thanks for the correction. Metric is not my first language. =) Some people think that putting the steel in the center is better but based on recent work I think it is best on the surface as it helps keep the cracks small where people see it and it is exposed to outside chemicals. Thanks again for watching!
thank You again professor- Unfortunately, have been involved in projects that have so much rebar, there’s little room for the concrete-a lot of lost denver vibrators. I believe that within our industry, we can pretty well predict where it will crack- but sometimes it just “depends”
Great explanations and I learned about Monier and his experiments. Your style is unique. I enjoyed the video a lot and I liked it and subscribed to the channel.
Thank you for sharing this video. Just want to share my observation when I was briefly assigned to Saudi Arabia, it's about plastic-coated rebars and tie-wires used (slab) without any sign of rusting even after 20 years. It would be great if there will be pre-cut rebars and plastic-coated for structural, so as to assure no metal exposure to cement.
You should try welded wire mesh. I've done designs with D 12 2 x 8 mesh in multiple layers for pipe design and you should see what happens when you mix it with 60MPa concrete. Unbreakable.
I read that putting rebar near outer surface of concrete is bad and there should be 1-3" buffer of concrete around any rebar to prevent spalling and protect rebar from moisture/rusting
Another informative vid. Thank you Tyler. But, I have a question for you. The Australian mine site I'm employed on is going through an expansion and update phase. This includes the removal of previously reinforced concrete to facilitate expansion. Apart from the mechanical impact destruction, I have questioned why the removed concrete debris, with reinforcement still semi intact but broken down into smaller peices by an onsite contractor, is being used as backfill, encased in a semi solid mortar that chemically sets with hours of application, than new reobar layed across this, which is than encased in what is referred to as a 'high tension cement. Just for technical interest, the backfill proportions are approximately 1.5 metres deep and the new HTC is approximately 1.0 metres thick. The areas are flagged as 'tank, silos and stationary machinery pads'. Their size varies greatly. I have never seen this questionable technique implemented on any site before. Is this a recognised procedure or a simplistic waste disposal ? Your thoughts please. 👍👍🇦🇺
Thanks for the question. What was the mine for? Maybe they think the material is contaminated and they want to contain it on site as opposed to moving it someplace else. It is hard to say.
@@TylerLey Iron ore mine. I should of added more detail to my question. Another question I forgot to include was whether this technique utilized would have any stability issues. There was no compaction of product, only product impact when dumped. As the average weight of mounted application will be 328 ton, I seriously question the engineering equations.
With respect to your pictures of re entrant corners you show 1 bar at 45 deg to mitigate cracking. On my re entrant corners I am considering a 30cm (10") radius to eliminate the hard 90 deg inside angle, with rebar following it round. However it would be quicker just to lay down straight rebar at say 30 and 60 deg, or even 3 sets at 22, 45 and 77. Your views greatly appreciated.
Find a metal stamper, the ones who run progressive dies- I ran a stamping plant and would save the skeleton -what is left from a strip of material after the part has been parted from the strip. I used these on several projects around the house, the material was 1/8 - make sure you agitate as the shape is irregular.
For basic gravity loads, is easy to grasp tension and compression loads. Add in the dynamics of seismic load and you need to consider different reactions. A basic equation for the seismic load distribution, Ai =1/ αi , is obtained based on the assumption that the velocity spectrum of the ground motion is independent of the period. Further, it is obtained from the maximum shear response using the elastic shear bar with both uniform stiffness and mass distributions. Through lessons learned (and still learning) some structures are designed stiff while others are designed flexible.
In the Philippines they put rebar too close to the outdoor surface and moisture seeps in and corrodes the rebar and the expanding corrosion cracks the concrete. They also lay the rebar on the bottom of the second floor or patio and same story the moisture seeps in and corrosion and cracks and also the rebar isn't doing anything except crumbling and falling on the floor below.
I love your passion Tyler. I have worked in construction for a major part of my life, but on crane crew not concrete, however I have watched the goings-on very closely when I have had the chance. I plan to retire in a tropical location about 8° north of the equator, and build a home about a mile from the sea, so I have a double-barrelled problem to deal with, the (I guess) salt-laden sea air, and an average relative humidity of 83%. Someone told me I should add Bondcrete to the mix, and (of course) make sure there is absolute zero exposed steel, and that should ensure longevity. Can you make any further suggestions please? Or if possible could you do a video focussing on tropical concrete or perhaps point me to one of your vids where you deal with this situation. I searched "tropical" in your videos but nothing came up.
Very informative. I work for Tindell. This is a wealth of knowledge to help me have a greater understanding of the mechanics behind my daily labor. #MorePlease
Very good video..... thank you. I have question though, for concrete on the ground why don't you put steel at the bottom side to prevent the curling ? At 6:32 you recommended to put the steel at top side...
Yes. Also, designing steel reinforcement at a significantly higher tensile strength than the compressive strength of the concrete is also a problem, because the concrete can crumble and fail well before the steel will show signs of yielding.
over reinforcements will be a problem for only surface cracks . nothing more . that crack might be sometimes deeper . doesnt matter once you patch it proper way
Hi I worked in the asbestos cement industry before asbestos was banned. While trying to replace asbestos with celullose fibre we were advised to high shear mix the cement with a very low water content. The idea was to remove the wetted surface of the cement particle thereby exposing the inner "dry" portion of the particle to the water and hence improving strength. Have you done any research on this .
Hello Professor I highly appreciate your wonderful discussion on the reason for using reinforcement, However, then why a concrete cylinder under compression fails with tension cracks due to hoop tension? Can we also explain this phenomenon and apply it to the necessity of stirrups in beams and ties in the columns? Please have a look at the following explanation and kindly let me know what is your opinion. I look into the necessity of rebar from a different angle based on the fundamental properties of brittle material. It comes from the basic characteristics of a brittle material like concrete which can not sustain plastic deformation so weak in mentions and brittle in response to loads. If concrete is not brittle or we may make it ductile like fiber-reinforced concrete (though not a 100% ductile material like steel), we may avoid shear reinforcements. Under compression load, any material (except a few which are engineered) will dilate due to Poisson's effect which would create tension in the transverse+hoop direction, and in the case of concrete (cylinders or cubes) under compression fails due to that tension along hoop direction. The compression capacity increased along with tensile capacity if we can confine the concrete along the hoop direction (as we retrofit concrete columns with Fiber Reinforced Polymer composite confinement, RC collar, etc.). In reinforced concrete design, the fundamental reason for using stirrups and tie rebars is to confine the concrete and thus to enhance the tensile capacity of the core concrete. If we cannot confine the concrete properly, no reinforced concrete can carry loads. We may create a finite element model of a reinforced concrete beam to observe the fundamental compressive principal stress distribution (the compression arch) under two-point load (AKA 4-point bending). We would see a compression arch formed starting from one support to another and peaking at the center. That means the locations of concrete under compression need confinement to enhance the tensile capacity of the core concrete to withstand the tension in the transverse direction, e.g., stirrups for confining concrete in beams and ties for confining concrete in columns/piles, etc. If we can confine concrete adequately, the compression capacity will increase a lot, however, the cost may increase as well, so by optimizing the cost and strength, the economical design is performed. We never use any stirrup in STEEL beams or tie in STEEL columns, however, we need different solutions for steel beams at high shear zone due to the geometry of the sections. Again, please note, stirrups and tie act as passive confinements, i.e., they get active only under loading. I hope you may provide your valuable comments. Please check the following articles for more information about dilation, principal compression arch in concrete, and specimens under flexure: ascelibrary.org/doi/10.1061/%28ASCE%29CC.1943-5614.0000599, ascelibrary.org/doi/10.1061/%28ASCE%29CC.1943-5614.0000599, ascelibrary.org/doi/abs/10.1061/(ASCE)CC.1943-5614.0000574 Sincerely
Remember, you asked for it. I want to build a garage over a basement. The garage floor will cover a free span of 24' x 24'. The top of the garage floor will be flat, the bottom slightly concave. The concavity should make the floor about 3" thinner at the center. I'm all for loading the concrete with macro- and micro-fiber, but am having difficulty justifying using FRP since none of the slab will be in tension. I'm in favor of adding super-plasticizers to reduce the number of large air pockets. I'd prefer the slump to leave the wet mix virtually flat, but that probably falls into the realm of the next hundred years.
Dr. Ley, Is there a rule of thumb for placement of longitudinal steel for an inverted cross section like an alleyway? Some place the longitudinal steel only along the wheel path (either sides of the invert) and some place it continuously (including the center) along the entire width? Thank you for these wonderful videos.
Curios of reinforcement design. I am building concrete patio, driweway 3m wide. I decided to use rebar with 0.4m spacing, at the bottom and top, so two layers of reinforcement. I think is better solution then add in the middle with 0.2m spacing. Average concrete thickness is 12cm, so either "middle" version has to press 6cm(if perfect in the middle, normally 4-6cm)of concrete to crack or ~8-10cm for two layer design. So I hope I gained double the strength with same materials, just more labor work. Since I do it myself, I don't mind.
Tyler - I wondered how can you tell the difference between chloride attack and carbonation, I inspected a building a found spalling concrete around rusting re-bar and did not know what had caused it? Many thanks from the UK
This bloke really reinforced his point at the end of the video. Thanks mate
Your comment really ought to have 13,000 likes.
Hey Tyler. I’m a reinforcing rod worker apprentice that just recently finished my level one training. We’ve watched most of your videos in class and they really helped us out a lot .
France during that period produced a number of exceptional thinkers and tinkers- Darcy's theories and formulas re how water (fluids) move through various densities of strata is still big when planning both water and oil wells. It was the industrial revolution and it's needs that were really receptive to new ideas. Bravo for shining a little more light on those tinkers and thinkers!FR
Thanks for pointing that out. So many great scientists and inventors from France.
@@TylerLey It was a great time for "critical thinkers" - the thresh hold of the Industrial Revolution. In America, Fulton and a host of others changed farming and laid the ground works for the greatest manufacturing boom ever- Henry Ford, the Wright Bros couldn't have happened with all that happened all over the world from about 1750 to 1900. Man's reach would finally be something he could actually see.
You are the guy that spent the time and got the degree- and then applied the bejabbers out of it! Me, I'm an over educated plumber, with a jones for the history of my own profession and the ones around it. I can retell stories about others who did big things- you, my friend are very likely to push into something no one ever foresaw! Good Hunting!FR
This is the first construction video that moved me to tears and calmed my fears!
Thanks so much!
Great engineering tips but brokendown in simple lay man language
Me too 💯❤️
Tear jerking video. Great information. My eyes are moist.
Thank you for making me a concrete freak too! I will be building a home in the Philippines and I have been studying SRC and many other aspects of civil engineering so I may be certain my home is built strong and safe. I have learned so much from you and your colleagues.
Thanks so much!
Be sure to study the techniques for making earthquake-safe concrete buildings. They have lots of earthquakes in the Philippines. Take a look at a map of the fault lines under the Philippines. Yikes! Also typhoons and flash floods. Pay attention to the elevation of your site, and to techniques for keeping your roof on in high winds. Maybe Tyler would be kind enough to make a video on planning a concrete building in such a high-risk area.
I am 60 year old structural engineer...my teachers never had this kind of passion ...
Thanks. 👍
Of course not , they just go home
I love how enthusiastic you are about concrete. This is the wonder of the internet. We can get connected to so many people who are so into their niche which gives us quality content like this.
The enthusiasm he shares during his videos could make any topic interesting, his subject: concrete. Viv la concrete!
that was just what i needed to know! THANKS
Brilliant. So many fantastically confounding topics covered in one video, abridged comprehensively . Thank you for your enthusiasm and diligence!!!!!!!!!!
Hahaha! He was a gardener?
Excellant. i have been in horticulture 60 years! And concrete work was a big part of our lives in creating things!
In College , i even took a 3 day intensive field class of the properties of concrete. In 1980, there was 2 of us women in that class of 25! That 1 weekend class gave me the science of concrete! As a landscaper & now on small ranch- thar knowledge has helped when i bulit my big corral & horse shelters!
Love your channel!
Another terrific video, enjoyed from the UK, thanks prof Ley.
I am so glad you liked it!
@@TylerLey 4:56 we do cranking there. bending bar 45o at tension reversal points
This video is a summary of what teachers are trying to tell in lessons of reinforced concrete, but they cannot. Maybe they do, but not make it fun like you! Thanks a lot! I really enjoyed listening you.- Greetings from Turkey
مش عارف ايش احكيلك بروف... لكنك فهمان وذكي وعندك معرفة كبيرة، وبحب احضر جميع مشاركاتك .. بالتوفيق تيلور
احكيله شكرا
@@ahlamddj حاضر
@@aqabajordan5356 Thanks, I think!!!
Tyler Ley He said : « I dont know what to say prof ... but you are intelligent and have great knowledge, i would love to attend all your classes... wish you success Tyler »
This guy is the Bill Nye of Concrete!
Today I learned something new about RCC ! Thanks mate .
Watching your video should help reenforce our diligence. Also thanks for the history lesson.
nice watch from someone who makes up rebar beams/cages for construction , now i want to see it being used and concrete being poured !
You explain so much better than my lectures. Now i really understand
Thanks for this. As an Engineer, this has made me learn more about concrete and reinforcement. Concrete is strong in compression but weak in tension that's the main reason why reinforcement is required. Doing this will eliminate or reduce cracks to be as minimal as possible. Well explained!👍
Great video. As being in the concrete construction trade for 35;years, I can attest everything you've mentioned is how we do it.
You give me a new love for structure. Im a fresh architecture graduate from Paris. Keep going !
The best series of base understanding concrete really easy to understand, therotical and pracrical usefull wery inspirering, thise infos are really neded in the industry.. Thanks a lot..
I have made so many mistakes myself, and payed the price, my mistakes made me look for better ways to do concreate, this is the best so far.
Thanks so much!
I agree that mistakes are so powerful. Keep sharing your lessons with others! Thanks again for sharing your experiences.
Love it Tyler. I don't know why I'm so fascinated with concrete, but I am.
Keep going!!!! It is the greatest material in the world!!!
Same i wanna build like small houses
This is so good! Love the narrating style! And lots of useful info. Thanks!
this video is so clear and straightforward, amazing work!!
Tyler, I think you’re the only person besides myself that gets giddy about concrete construction. I’m not a DIY home owner...oh wait...I guess I am, I just happen to have a General Engineering and General Building license in California for about 40 years. I’m getting ready to design a, my first, post tension sog in northwest MO. I’m so happy 😁 !
That is so cool! Let us know how it goes!!!
I LOVE HOW ENTHUSIASTIC HE PUTS ON HIS SUBJECT
Excellent lecture 👍.... Thanks for your video.... I am waiting for your next video from INDIA ....
I always wondered why they put plastic before concreting. Now i understood.thank u tyler
I learned too, I thought it was only to aid in hydration. Never considered plastic sheeting lessening friction to avoid cracking.
@@Gary-pogi yes yes
Also for an air and water barrier.
hello from Malaysia. great video! the way you give the explanation surely shows you're a concrete freak, and i love it! keep em coming
OMG! I really love your explanation.
Thanks sir.
This is the first video that I have learned from, it changed my mind about reinforced
I'm excited as heck about concrete now.
Very interactive video indeed......thanks for sharing Monier’s inspiring story
as a UG Trainee engineer this is so helpful
I love you dude! You are such a good teacher! Thank you so much for all your hard work and explaining thing so simply so I can actually understand! God bless you bro!
Thank you so much!!!!
Thank you so much for this information. This will help me with teaching my students about rebar works.
You videos are easy to understand and follow. Thank you.
You are crazy energetic when you lecture - I love it!
Thanks Tyler! Complexity broken up into simple concepts & practical solutions. Also, the gray background is perfect.
I am pouring some footings for a pergola I am making and I put a rebar "cubes" in each one because of your channel.
I am glad it helped!
perfect tutorial. thanjs also for talking about our great Mr Monier. you are the best.
Thank you so much for the kind words. GO FRANCE!
Ur lecture so excited ....i want to know more about concrete properties
Many you really cheer us up. Great job mate!
Thank you so much!!!
Thanks for posting this video. You made it interesting and amusing.
This video was amazing, and the motivational quotes at the end were very appropriate for me in this moment of my professional life. Thanks, Tyler.
Keep going! The amazing things are just beyond the pain. You can do it!
Love the passion; absorbing the facts.
Great Content! Watching from Philippines
We see Prof. Ley’s New Video, We Directly Watch it.
You are my new Netflix 😂
Superb Explanation Tyler..I loved it
The ground will heave and contract. I introduce the red clay we have in some parts of north central Texas, NW of DFW about an hour or so. 1+" cracks in the ground in the summer, zero cracks in the wet(ish) months. Slabs on grade can heave and fall at the perimeter and, the clay under the center area will dry out and contract, leaving voids under the concrete if there are sufficient piers to support it or turning the slab into a cereal bowl if there aren't. It's not just the friction of the soil holding the slab from expanding and contracting causing tension horizontally, it's the up and down at the edges as the soil gets wet and dries out and the depression in the center as the clay dries out never to get wet again (covered with concrete).
Hey Tyler, love your work and your personality. My gosh your energy is contagious and fun! Keep up the good work it is fascinating!
Another excellent video; well explained. Maybe a demo of a beam cracking with and without reinforcement.
Minor point at 08:10 you mention the steel should be 1.5" from the top (67mm) hmm I think it should be (40mm).
I only point it out as lot from around the world will see the metric.
I see too often builders think the steel mesh should go in the center of the slab for slab on grade/ground.
Cheers
Pulpo
Pulp! Thanks for the correction. Metric is not my first language. =)
Some people think that putting the steel in the center is better but based on recent work I think it is best on the surface as it helps keep the cracks small where people see it and it is exposed to outside chemicals.
Thanks again for watching!
thank You again professor- Unfortunately, have been involved in projects that have so much rebar, there’s little room for the concrete-a lot of lost denver vibrators. I believe that within our industry, we can pretty well predict where it will crack- but sometimes it just “depends”
excellent teacher u are...from south africa
Great job with this video. Taking a deputy inspector course for reinforced concrete now and this is very interesting and helpful.
Great explanations and I learned about Monier and his experiments. Your style is unique. I enjoyed the video a lot and I liked it and subscribed to the channel.
Thank you for sharing this video. Just want to share my observation when I was briefly assigned to Saudi Arabia, it's about plastic-coated rebars and tie-wires used (slab) without any sign of rusting even after 20 years. It would be great if there will be pre-cut rebars and plastic-coated for structural, so as to assure no metal exposure to cement.
dude so great information so enjoyable to watch ... keep up !
Thanks!!!
Very informative. Check your conversion at 6:28. 1,5" is 38mm and not 67mm
You're a pro! You've done a wonderful job.
Awesome work. Thank you very much
Superb explanation Tyler..I too am very interested in concrete reinforcement
You should try welded wire mesh. I've done designs with D 12 2 x 8 mesh in multiple layers for pipe design and you should see what happens when you mix it with 60MPa concrete. Unbreakable.
Wow..I am going to be a Future Engineer because of you ❤️
I read that putting rebar near outer surface of concrete is bad and there should be 1-3" buffer of concrete around any rebar to prevent spalling and protect rebar from moisture/rusting
Another informative vid. Thank you Tyler. But, I have a question for you. The Australian mine site I'm employed on is going through an expansion and update phase. This includes the removal of previously reinforced concrete to facilitate expansion. Apart from the mechanical impact destruction, I have questioned why the removed concrete debris, with reinforcement still semi intact but broken down into smaller peices by an onsite contractor, is being used as backfill, encased in a semi solid mortar that chemically sets with hours of application, than new reobar layed across this, which is than encased in what is referred to as a 'high tension cement. Just for technical interest, the backfill proportions are approximately 1.5 metres deep and the new HTC is approximately 1.0 metres thick. The areas are flagged as 'tank, silos and stationary machinery pads'. Their size varies greatly. I have never seen this questionable technique implemented on any site before. Is this a recognised procedure or a simplistic waste disposal ? Your thoughts please. 👍👍🇦🇺
Thanks for the question. What was the mine for? Maybe they think the material is contaminated and they want to contain it on site as opposed to moving it someplace else. It is hard to say.
@@TylerLey Iron ore mine. I should of added more detail to my question. Another question I forgot to include was whether this technique utilized would have any stability issues. There was no compaction of product, only product impact when dumped. As the average weight of mounted application will be 328 ton, I seriously question the engineering equations.
With respect to your pictures of re entrant corners you show 1 bar at 45 deg to mitigate cracking.
On my re entrant corners I am considering a 30cm (10") radius to eliminate the hard 90 deg inside angle, with rebar following it round. However it would be quicker just to lay down straight rebar at say 30 and 60 deg, or even 3 sets at 22, 45 and 77. Your views greatly appreciated.
You sir are a true Hero. Thank you
I loved it and understood every word of it ...thank u dear
Find a metal stamper, the ones who run progressive dies- I ran a stamping plant and would save the skeleton -what is left from a strip of material after the part has been parted from the strip. I used these on several projects around the house, the material was 1/8 - make sure you agitate as the shape is irregular.
For basic gravity loads, is easy to grasp tension and compression loads. Add in the dynamics of seismic load and you need to consider different reactions. A basic equation for the seismic load distribution, Ai =1/ αi , is obtained based on the assumption that the velocity spectrum of the ground motion is independent of the period. Further, it is obtained from the maximum shear response using the elastic shear bar with both uniform stiffness and mass distributions. Through lessons learned (and still learning) some structures are designed stiff while others are designed flexible.
These videos are pure awesome.... especially the crack sound effects :) haha
Great video Tyler
In the Philippines they put rebar too close to the outdoor surface and moisture seeps in and corrodes the rebar and the expanding corrosion cracks the concrete.
They also lay the rebar on the bottom of the second floor or patio and same story the moisture seeps in and corrosion and cracks and also the rebar isn't doing anything except crumbling and falling on the floor below.
I love your passion Tyler. I have worked in construction for a major part of my life, but on crane crew not concrete, however I have watched the goings-on very closely when I have had the chance. I plan to retire in a tropical location about 8° north of the equator, and build a home about a mile from the sea, so I have a double-barrelled problem to deal with, the (I guess) salt-laden sea air, and an average relative humidity of 83%. Someone told me I should add Bondcrete to the mix, and (of course) make sure there is absolute zero exposed steel, and that should ensure longevity. Can you make any further suggestions please? Or if possible could you do a video focussing on tropical concrete or perhaps point me to one of your vids where you deal with this situation. I searched "tropical" in your videos but nothing came up.
Very informative. I work for Tindell. This is a wealth of knowledge to help me have a greater understanding of the mechanics behind my daily labor. #MorePlease
Love the guy's spirit
Very good video..... thank you. I have question though, for concrete on the ground why don't you put steel at the bottom side to prevent the curling ? At 6:32 you recommended to put the steel at top side...
Cool informative video.. Subscribed
Regards from Egypt ✌️
Thank you!!!
Over Reinforcement is a problem too! Go engineers!
Specially when it comes time to knock it down, or pay the steel bill.
Yes. Also, designing steel reinforcement at a significantly higher tensile strength than the compressive strength of the concrete is also a problem, because the concrete can crumble and fail well before the steel will show signs of yielding.
over reinforcements will be a problem for only surface cracks . nothing more . that crack might be sometimes deeper . doesnt matter once you patch it proper way
Much respect for shearing education of construction we need more and more skills
The cool thing about cracked pots in particular is that terracotta forms a hydraulic bond with lime to make especially strong concrete.
As a union carpenter, that does tons of structural concrete, I love this video.
Hi
I worked in the asbestos cement industry before asbestos was banned. While trying to replace asbestos with celullose fibre we were advised to high shear mix the cement with a very low water content. The idea was to remove the wetted surface of the cement particle thereby exposing the inner "dry" portion of the particle to the water and hence improving strength. Have you done any research on this .
What are your thoughts on multiple layers of fibers? Each layer a different fiber material based on your video.
I love your style of teaching bro
Hello Professor
I highly appreciate your wonderful discussion on the reason for using reinforcement, However, then why a concrete cylinder under compression fails with tension cracks due to hoop tension? Can we also explain this phenomenon and apply it to the necessity of stirrups in beams and ties in the columns? Please have a look at the following explanation and kindly let me know what is your opinion.
I look into the necessity of rebar from a different angle based on the fundamental properties of brittle material. It comes from the basic characteristics of a brittle material like concrete which can not sustain plastic deformation so weak in mentions and brittle in response to loads. If concrete is not brittle or we may make it ductile like fiber-reinforced concrete (though not a 100% ductile material like steel), we may avoid shear reinforcements. Under compression load, any material (except a few which are engineered) will dilate due to Poisson's effect which would create tension in the transverse+hoop direction, and in the case of concrete (cylinders or cubes) under compression fails due to that tension along hoop direction. The compression capacity increased along with tensile capacity if we can confine the concrete along the hoop direction (as we retrofit concrete columns with Fiber Reinforced Polymer composite confinement, RC collar, etc.).
In reinforced concrete design, the fundamental reason for using stirrups and tie rebars is to confine the concrete and thus to enhance the tensile capacity of the core concrete. If we cannot confine the concrete properly, no reinforced concrete can carry loads. We may create a finite element model of a reinforced concrete beam to observe the fundamental compressive principal stress distribution (the compression arch) under two-point load (AKA 4-point bending). We would see a compression arch formed starting from one support to another and peaking at the center. That means the locations of concrete under compression need confinement to enhance the tensile capacity of the core concrete to withstand the tension in the transverse direction, e.g., stirrups for confining concrete in beams and ties for confining concrete in columns/piles, etc. If we can confine concrete adequately, the compression capacity will increase a lot, however, the cost may increase as well, so by optimizing the cost and strength, the economical design is performed. We never use any stirrup in STEEL beams or tie in STEEL columns, however, we need different solutions for steel beams at high shear zone due to the geometry of the sections.
Again, please note, stirrups and tie act as passive confinements, i.e., they get active only under loading. I hope you may provide your valuable comments.
Please check the following articles for more information about dilation, principal compression arch in concrete, and specimens under flexure:
ascelibrary.org/doi/10.1061/%28ASCE%29CC.1943-5614.0000599, ascelibrary.org/doi/10.1061/%28ASCE%29CC.1943-5614.0000599, ascelibrary.org/doi/abs/10.1061/(ASCE)CC.1943-5614.0000574
Sincerely
So wonderfull lecture.. need a lecture about plinth beams it will be very helpfull if you provide this on your channel
Please can you do a video on raft foundation , and please why do we have extra additional layer of reinforcement in a raft foundation
I really value seeing your vids.
Thanks so much!
Remember, you asked for it. I want to build a garage over a basement. The garage floor will cover a free span of 24' x 24'. The top of the garage floor will be flat, the bottom slightly concave. The concavity should make the floor about 3" thinner at the center. I'm all for loading the concrete with macro- and micro-fiber, but am having difficulty justifying using FRP since none of the slab will be in tension. I'm in favor of adding super-plasticizers to reduce the number of large air pockets. I'd prefer the slump to leave the wet mix virtually flat, but that probably falls into the realm of the next hundred years.
The ground does move, so rebar is necessary to account for the soil shrinking/swelling/consolidating causing tension in concrete?
Thanks for the great video
Dr. Ley, Is there a rule of thumb for placement of longitudinal steel for an inverted cross section like an alleyway? Some place the longitudinal steel only along the wheel path (either sides of the invert) and some place it continuously (including the center) along the entire width? Thank you for these wonderful videos.
Curios of reinforcement design. I am building concrete patio, driweway 3m wide. I decided to use rebar with 0.4m spacing, at the bottom and top, so two layers of reinforcement. I think is better solution then add in the middle with 0.2m spacing. Average concrete thickness is 12cm, so either "middle" version has to press 6cm(if perfect in the middle, normally 4-6cm)of concrete to crack or ~8-10cm for two layer design. So I hope I gained double the strength with same materials, just more labor work. Since I do it myself, I don't mind.
Thankyou for the video.
Small mistake there...1.5" is not 67mm right.
Tyler - I wondered how can you tell the difference between chloride attack and carbonation, I inspected a building a found spalling concrete around rusting re-bar and did not know what had caused it?
Many thanks from the UK
subbed! very informative! and you broke it down so well even my dog would understand it.
HA!!! Thank so much!