How Strong Is Concrete? Hydraulic Press Test! 

Very interesting video. For the next experiments with concrete, try bending loads. Try mixing your own concrete, too.

@@lajoswinkler "Try mixing your own concrete, too." yeah, especially with rebar ;)

AWESOME VIDEO.....Thanks very much from USA🇺🇸

Have a very nice and relaxing holiday.

You should try with Roman concrete now that we know the recipe

No they gonna crush the atom :D

If they get into nuclear testing, they'll be testing fusion, not fission.

@@supersim81 - They will collapse the Neutronium sample they have and cause a total protonic reversal where it opens a black hole and the press slips through a hole in spacetime and ends up in another part of the universe. I know for sure because I learned it from Captain Proton on TV and I am wearing my Hydraulic Press Enganeer Hat LOL. They will discover that in the space on the other side is every sock, glove, shoe, and everything else that anyone ever lost. That is where they go. (YA DURAK)

Accidentally starts a fission reaction

Lowri, "where's my chisel" In an Australian accent. (Young Einstein thoughts there).

I’m sure it’s been maintained properly and had components replaced or rebuilt overtime.

It did have a problem once or twice with the hydraulic lines popping off after stuff exploded. That's all I can think of though.

@@MrNukealizer given the amount of force that is applied, that’s to be expected. Rubber hydraulic lines grow old and fail at times too.

@@PereMarquette1223 Might be hard to believe but I have only replaced on connector during the 8 years :D Sure there is some explosions but other than that it has been on quite little of use. We run it maybe 3 hours per week on average. On some jobs these might run 24/7 for many years without any problems.

@@PereMarquette1223 This has steel lines so no worries about those breaking

They've crushed my hopes of ever matching their subs

Agreed!

Just imagine if they spoke English, 20m sub's !

Interesting

Ive done it and I can say it depends on the age of the sample cylinder and the material its made out of. With weaker mixes the Structural intergrity of the cylinder is compromised already theyre often softer will it change the break pattern though NO. It shouldnt change the break pattern thats the whole point of Compressive Strength testing you want it to bust under load the same regardless of if you press it new limits and stop and doing it again or not. Youre simulating load conditions. How the break occurs is vitally important structural information. There are numbers that they go off of referring to the breaks typically one the busts and crumbles through our and cracks center would be a 4 one that shears and breaks the edges and holds strong with be a 5 on the ratings. I think there was anotehr number but its been close to 20 years now.

You can do the psi to kg conversion in your head ?

@@gavinhay6627 hell no. He listed the load weight in KG and lbs.

as a tester can you comment on the fibers? from my recollection they are there to mitigate sheering forces not compression. like the first concrete test actually looked like it sheered vs crushed.

@@miza6 that is correct. Fibers do not add any significant compression strength.

@@miza6 As a career concrete guy, I’ve only had the concrete spec’d with steel fiber used once on a job and it was used specifically for heavy duty wear properties. It was used for the floor of a new loading dock ramp at a trash recycling facility.

We have also really flexible press. The table bends something like 10mm so the explosiveness comes from that mostly

I have been working with this to for many years in my previous job. We tested with cubes, and it was not uncommon that they exploded, but that only happend with the strongest types of concrete after 28 days. But this was a really interresting video non the less! 🙂

Depends on the Press the one I used had a swing handle and it went at a set speed you couldn't make it go faster or slower. When I tested Cylinders they almost always exploded I forgot about the 28 day Break its been a long time ago for me.

@@Alpejohn The Cylinders do too its pretty common I blew my door off the machine often. Usually the older ones got the big pops but sometimes a 7 day break could do that as well. Depends on who the Job was for. I didnt test many of the tiny cubes those were not much fun to test any how lol. We did soil samples with sulfur caps as well.

I think I could try with stupid add-ons :D

@@HydraulicPressChannel Only yesterday I was thinking about medieval concrete, and what they might have tried to a) make it stronger, and b) make more concrete for a given ammount of lime.

@@HydraulicPressChannel concrete + cornflakes = ?

@@hermitoldguy6312 There was no medieval concrete. The Greeks and Romans had a form of structural concrete using natural pozzolana but the technology was lost in the dark ages. Inferior slaked lime mortars were used until Portland Cement was developed in the early 19th century. The slaked lime materials were too weak to create structural forms from. The Pantheon in Rome is an example of Roman concrete construction.

They add carbon and other materials then also heat up the water when making it@@hermitoldguy6312

Usually we only did the sulfur caps for Soil Sample tests I didnt do much of that for the concrete cylinders. The Sulphur is heated to the flash point.

$10 in 1978 is at least worth $46 today. You're telling me you got paid $46 out of high school with no experience? Fml

I suggested something similar last time they tested concrete. I was ACI certified 20 years ago, used to run a concrete plant. 1. Not sure what euro standards are, but those cylinders were not made properly under ACI standards. you do not vibrate cylinders 2. If those were 8 inch cylinders, then you guys got roughly 3100psi, not that strong really. especially if that was granite they used as aggregate. 3. rubber or sulphur endcaps are the correct way to break cylinders. 4. have the company make some proper concrete, using things like a high range water reducer, a retarding agent, a high cement content, and silica fume/flyash if you can find it. Euclid chemical is the place to start in the USA, not sure about the EU. 5. if you do this, you will likely end up in the 12,000 psi range or even higher if you cure it correctly for 28 days. 6. only make a 4 inch cylinder, fill it in three layers, and only rod each layer about 10 times(I forgot the actual number here), screed off top and leave it. 4 inch cylinder is necessary as their machine likely couldn't break an 8 inch cylinder of this stuff as you would need at least 271,000kg of force if done correctly. follow this and if you can break it, it will be loud for sure. last time I tested stuff like this, the midsection literally exploded.

Yeah, or a board or something

We use a cylinder end grinder at work, we only use sulphur on cores we can’t grind.

I think under these loads, a sheet of lead or copper may work well

​@@ANATURALDREWSASTERthe steel of the flexible press is probably ample tho, yea?

@@davidsmixer That's not Anni, that's Hanna. Anni is up in Lapland, and is no longer married to Lauri. All three are on completely friendly terms, though, so no drama whatsoever.

Concrete is relatively weak in tension so would fracture easily, hence the use of rebar

We've used the plastic fibers before, they're used to replace wire mesh pouring floors.

Fiber additives aren't that much in regular use, but when building big warehouses etc. it's used. Reduces rebar usage a lot and much cheaper faster to lay down big slabs on one go. Pain in the ass to use tought, and all cement mixers and pump drivers hate 'cause it chews up all rubber hoses so quick.

We use poly fibres in Ontario pretty frequently. It interferes with a polished floor finish so we usually use it for stuff like loading ramps or parking. If you are putting wire mesh it can usually be substituted with fibres. Warehouses will have steel fibres.

The Bible mentioned mixing in straw, so in the 1980s someone tried doing that in concrete, thus inventing fibre reinforced concrete .

@@johndododoe1411, writes _"The Bible mentioned mixing in straw, so in the 1980s someone tried doing that in concrete"_ from wikipedia: _Historically, horsehair was used in mortar and straw in mudbricks. In the 1900s, asbestos fibers were used in concrete. In the 1950s, the concept of composite materials came into being and fiber-reinforced concrete was one of the topics of interest. Once the health risks associated with asbestos were discovered, there was a need to find a replacement for the substance in concrete and other building materials. By the 1960s, steel, glass (GFRC), and synthetic (such as polypropylene) fibers were used in concrete. Research into new fiber-reinforced concretes continues today._ So, you're wrong. P.S. Look up _wattle and daub._

Did they explode this much? Or is it just my press that throws things around :D

@@HydraulicPressChannel The lab I was a part of had shielding around the press. There were holes in the drywall behind the press that shot through the spaces in the shielding sometimes.

Also did you ever add the faces to these :D

@@HydraulicPressChannel Much more character to your 6" cylinders.

@@HydraulicPressChannelDetails are fuzzy (it’s been a few years), but generally we stopped pressing once we noticed the concrete had failed, but before it exploded. As you probably know, you can tell because the force stops increasing while the deformation increases. However, sometimes we missed it or were bored, and the cylinder just went. Of course we had shielding around it and PPE

Wall made outof concrete laid on its side? I'm trying to visualise what you mean. Do U mean like a wall made outof a mortared stack of small concrete bricks? Edit: OOH sorry I missed U saying it was made of these test cylinders. That makes sense.

@@roidroid Ha ha, no worries. Like those bottle walls and even houses. There was a famous one up near Noosa?🤔 Might have the location wrong.

ROFL! Good pun!

That’s also the reason for the reinforcing steel (rebar).

Concrete provides very little pulling strength, so an encased compressed spring would push itself out . Concrete buildings are held together by steel, concrete just prevents it from crumbling .

It does. Exposed to fire, small pockets of moisture in the concrete boil and explode, spalling it badly. They just demo’d a bridge section of I-95 that had a tanker explode underneath it. Ruined the structural integrity.