I'm developing my master's degree tesis on this topic and academic stress helped to make me forget the beauty of this topic. Your passion, sir, gave me a fresh breath and remainded me this is AWESOME. Thank you for your video and keep on being a passionate concrete freak!
I only wanted to see what a fiber cement looks like but I ended up watching the entire video lol. This is so informative and the way it is presented really made me interested. Thanks for this!
Thanks Tyler for your quality videos. I am a retired contractor now full time artissn / craftsman in deep play with cementious materials. I just recently did your channel and would like to express grattitude for your enthusiasm and willingness to share. Thanks
Hey Tyler, here is AU I came across fiberglass woven mat where the woven strands are every 2mm and is a 6 oz mat. I've used these in garden bed walls that can be walked on with heavy wheel barrows. 20 years on and not a crack. Basically I lay 30-40 cm of concrete then the first mat, another 40cm concrete and second mat and keep going to the relevant height required.
Dear prof. Ley, My name is Jang. I'm college student in Korea, University of Seoul. I'M REALLY DOPPED in your channel about conc. Now, i'm in major of UHPC(Ultra high performance concrete) and its piezoresistivity. If you don't mind, would you upload a clip about UHPC on RU-vid? Thank you for reading my direct message :)
Hi, Mr. Ley. I have not used fibers in my projects, but for my civil engineering materials end of semester presentation, I may summarize some of the current research of fiber reinforced concrete. Your video has inspired me and helped me to select my topic.
Dr Ley, I have been getting push back from Contractors especially on slab on grade application. There argument is it is challenging to finish, like you showed on your video. I like the video it is truly helpful.
Try adjusting the paste volume of your mix with fibers. Make a designated mix design with fiber built in. I find a 30-35% paste volume works well with typical macrofiber
@lackoffkgivity most of these issues can be fixed with paste volume and using clean aggregate Also don’t throw all the fibers in at once. Do one bag at a time slowly
After learning all about concrete over the past few years from watching and rewatching your videos (among others) I'm now standing here in Costco having an aneurysm that they didn't fiber reinforce their beautiful densified concrete floor! So many cracks!!!!
Ryszard, This is a good question. In my opinion there is not a lot of good data on this. Most testing has focused on the strength of the fiber reinforced concrete after it has cracked. I am not sure this is really what is important. I think it is better to focus on how well the fibers can keep the cracks small. Also, most of the testing is from external loading. Very little work has been done to investigate the performance in cracking from freeze thaw or drying shrinkage. While is known that the micro fibers only really help at early ages, no one has really quantified how much they help. We are starting to work a lot with fibers in my lab and so stay tuned for more details.
@@Veldtian1 All the companies listed on the Fiber Reinforced Concrete Association (fiberreinforcedconcrete.org/) are great suppliers of quality plastic fibers. Check out the site!
I know basalt does not rust, expand, or corrode like steel, is ultimately stronger yet extremely brittle, failing abruptly. Specifically, basalt is less rigid (1/3) than steel rebar in the steel's elastic sense, but has a much higher ultimate strength. But when it does fails it does so abruptly and totally. There is little warning, so safe evacuation of structures is dependant on active monitoring of abnormal stress, which requires planning and fidelity. Basalt fabric has properties that have not been properly exploited by industry. It can be placed at the surface of concrete so that it's tensile strength minimizes initial cracking. However _prestressing basalt_ fabric has not been investigated enough.
Tyler, it's been too long, glad to see this post AND it's on a question I ask you about quite awhile ago. Awesome video, worth the wait! Thanks for continuing to teach us about concrete. Never would have guessed how complex and interesting a subject, concrete is. Can't wait for more!
Micro fibers= cracks 1-6 hours Macro fibers= cracks days to years I used to be a driver now I'm a batch man so I'm watching all your videos on concrete so I can sound smarter 😁
7-VII-2021.We artist have been using fibers in our clay plaster and concreat sence the the Renaissance, today we have green strenth and fired strenth fibers, in Malta my Greath Grand father pionerded the usage of fibers in concrete back in 1906. Much more to tell you about.
Have you considered for steel fibers using magnetic flux field to align the fiber direction. Example is iron particles on paper that have a magnetic field extending through the paper shows the alignment. So assume that you can lay the concrete into a form in the direction that you want the fiber majority to be aligned to. One way of aligning them is a use a tube with DC current flowing through wire wrapped around the tube. The flux field will be parallel to the axis of the tube and flow direction.
I would think the density of concrete would require a very strong magnetic field and that would draw the fibers to that side of the pour. Remember your example is in a very nonresistive medium(air) and the filings are being kept separated from the magnetic source by the (relatively) strong paper.
Thanks Thomas! William is right, it is very hard to get the fibers to align where you want them to. Also you need a very strong magnet. However, maybe somebody can figure this out. Someone should try and make it happen.
Maybe magnetic alignment could work whilst the concrete is being vibrated, because everything would be more mobile. Interesting idea. Test it yourself and make a video :)
Metal in concrete is a bad idea especially in humid climates. Metal will expand and contract causing cracks. That and metal rusts like a bitch in concrete because of water.
I specified fiber reinforced concrete once. It was a pad for a portable MRI at a hospital. It was moved from place tp place in a semitrailer. I wanted to keep iron or steel away from near it because that would affect the image and the machine would have to be “shimmed” or adjusted each time it was parked before it was used.
We are pouring a 1 to 6 inch topping slab on a WWT plant containment SOG. 130 foot x 100 foot. 4 foot high containment wall all around. All concrete has rebar, topping slab has microfiber reinforcement. Trench drain along centerlines.
Im going to use both Owens Corning 32-500 fibers and a fiberglass rebar grid in my wood stove hearth. Im hoping it will increase the strength and minimize cracks.
Hey Tyler, much thanks for all your information! I'm trying to line a cave I have on my farm with concrete, but without using steel... The alternative would be using the more than thousand year old method of combining wood and mud, as has proven successful in Europe, with those houses standing for over 1,000 years with only minor repairs...
Thanks a lot Tyler. Love the way how you make complex topics simple. I had one question though. What if we use Glass fibre mesh instead of the fibres? Will it solve the alignment problem?
Thought: if you poured a few inches of concrete, and then placed a sheet of fiberglass in the area of the most stress, and then repeated, concrete and glass sheets? This would be instead of random fibers, and would be in addition to rebar.
I've had a garage floor that needed to make up a 1/2" gain in height- we mixed in fiber (fiberglass strand type) and trowed to a smooth finish. While not directly exposed to the elements, it has had cars, trucks, etc. worked on with jack stands, etc for over 10 years. still holding up well, in the freeze/thaw climate.
Tyler, that will be a hard one, but I will try to check. it wasn't that much, because it was actually mixed by hand. I will try to find the left over packets of fiber, but I think it was roughly one ounce to 50lb dry, course sand, no klinker. I love your channel!
Suggestion for coming video - how to repair old concrete with new. The problem often seen is that the repair cracks off from the old concrete, like when an outdoor concrete staircase is repaired.
Starting looking at replacing my driveway in northern climate, and the contractor says he uses sika micro fiber in mesh + dowel steel rebar. Not knowing what any of that meant, and coming from warmer climate, I thought a steel fiber mesh was necessary, but seems tech has changed a ton
I used microfiber to test its influence on mitigating autogenous shrinkage but I got negative results. It seems the kind of fiber I used increase the self desiccation of cement paste.
We like to use micro fiber on our slabs regardless we have rebar or WWM -- have not tried @ a column and beam levels before... will look to try on our next pour
Hey great info. What would you do for a Barndominium concrete slab where half the building will be habitable and concrete will be polished with underfloor heating and the other half will be garage/workshop.
hey Tyler. I'm a concrete finisher and so glad i found your channel. question:. why would my concrete driveway crack right next to a control joint months after we poured it. thanks.
Not all fibbers r the same is a great statement. Most finishers r trying to replace rebar with fibber to save in labor. It’s not made of that. In most applications. In my experience plastic cracking is cause is high heat and pouring concrete to wet in that heat. The drying happens to rapidly and causes shrinking/plastic cracking. Happen to me once in my 27 years this summer in 2020 South Louisiana heat
I need to patch several pot holes in a parking lot. The traffic is light but there is forklift, 4000Lb, and tractor trailer deliveries. Would fiber reinforce concrete say 4-6 inches in the bottom of the pothole with asphalt patch on top work? This is in a desert environ, southern Utah, very little rain and hotter than hell in the summer.
I worked on a new warehouse, we used fibered concrete with fiberglass and8x9 wire reinforcing. There was something special about the concrete besides the fiber, but I forgot what that was.
Sir, recently heard that, colloidal silica use in concrete as an admixture. My question is why colloidal silica use? And what is the optimal dosage of colloidal silica in concrete mix design?....thanks for educated us for make better concrete...
Thanks for all your videos, I am planning a workshop build and every concrete contractor has a different idea of what would be best. Educating myself with your videos are helpful through this process. Do you have any videos or insight on how in Slab radiant heat with under slab insulation effects concrete? Thanks again.
Very difficult to find distributors that will sell macrosynthetic fibers to the public at large. You have to be a company that orders them by the pallet. I have found a few places that sell micro however.
When it comes to fiber reinforcement, you can even use cotton balls. I’ve tried it with small ice cream buckets, I froze one with just water, the other with water and cotton balls, then shot both of them with 9MM. The one with cotton balls took more hits and lasted longer.
Just had a contractor extend my back patio. I wasn’t aware of this “microfiber” method. When they were done and I lifted up the tarp it looked like a bunch of grass was embedded in it turns out this stuff is the microfiber. The contractor told me that they will eventually go away is this true? It looks pretty bad at the moment
Do you put a thin layer of concrete without fibers, for example, in a mold, then add more with fibers? Otherwise, the fibers may be seen on the surface.
I worked in a mine that you would drive in and out of in vehicles with rubber tires. They use the shotcrete (concrete) with the steel fibers to reinforce the roof and walls of the mine. Many flat tires later, they stopped using steel fibers.
clearly explained, thanks. I am trying to decide if i should use steel mesh or fibers in my 10 inch tubes for the footers under my shed. I am in savannah, so there is no frost line, and my footers are not very deep.
Thanks for the helpful videos. For building sculptures, I was hoping I could shred my own recycle plastics to use as macrofibers. Any reason not to do that?
I’m a relatively new subscriber to your excellent channel. I therefore don’t know if you’ve covered this elsewhere, but I have a question about the global sand shortage. I’ve seen beach sand vs. desert sand under a microscope and understand very well how the former is infinitely preferable for making concrete over the latter, but couldn’t excellent concrete be made with desert sand (of which there is no shortage whatsoever) plus micro fibers plus macro fibers?
Hello sir I am pursuing Masters of engineering ,and my dissertation topic is GFRP as rebar in concrete, and I choose to cast one way slab using GFRP rebar. But don't clear the design philosophy, I read the ACI 440 code but never clear from it . So please share something on it Thanking you
Hi, I just had a 5" fiber reinforced concrete slab poured for my future garage. Do I need to wait a MONTH to stain and seal it? Thanks so much for any information!!!
super light concrete could potentially benefit from fibers: organic, natural, metalic , wich will last longer? concrete absorbs humidity and stores it?
I am planning to make a small drainage. 50 ft in length, 6 inches wide, 2 inches side wall, and 1 inch thick. Do i need these fibers or should i just use 1"x1" wire mesh?
Reminds me of horsehair plaster! Is there a method of aligning the fibers to control the way they will support stress? Perhaps running some sort of comb through the wet concrete in a single direction?
What if you added a sheath of reinforcing material around the concrete, like covering it in carbon fiber composite, creating a honeycomb. The composite would take the normal forces and the concrete could be the web and take the shear forces. Aerospace engineer here, so I don't know diddly squat about concrete, just wondering.
Actually the infamous asbestos is a fiber as well. I am about to use fibers and i decided to use PVA over glass fiber. Based on my research its a really good stuff, but i had no chance yet to work with.
Read about James Hardie and CSR here in Australia, Asbestos fibre was used extensivelly here in fibre reinforced cement, basiclly every house was built using it at the time
Would you put hempcrete into this category and any research you have done on Graphene reinforced concrete ? "Graphene reinforced concrete is twice as strong and four times more water resistant. ... Crucially, the new graphene-reinforced concentre material also drastically reduced the carbon footprint of conventional concrete production methods, making it more sustainable and environmentally friendly'
From a suppliers end, it is a constant struggle to convince contractors set in their ways to use fiber. I think they are essential use on residential jobs, as that is where lack of QC tends to come in the most.
with macro fiber it really hard to bring slumps up to 7-8 inches. even if using high range water reducers. and water cement ratio should be brought down.
Can you still seal micro fiber concrete. I recently had a patio poured and it has microfibers. I can see them. It is also dusting due to poor prep by my contractor. This is why I want to seal it. I greatly appreciate any response and knowledge.
Therty years ago I sprayed FRC from a gun. We had a 50-50 sand cement ratio hey that we sprayed on 2 latex molds of rock texture. And then with the next pass we mixed in chop with a gun at the end of the nozzle. This gave us 4-foot by 8-foot panels of textures like sandstone granite limestone lava and marble. We even made a pirate ship for Disney world.
