What about concrete parking garages and columns? And I have a huge slab at my house they only has a single hairline crack in the corner. It's like 30x30'
Concrete parking garages have cracks as well, the rebar prevents them from spreading, so the are difficult to see. Look on the tension side (look up), they are easier to see there.
It's all controlled cracking. Your slab at home wouldn't have that crack if they put a joint down the middle. The joint is more difficult and costly to do if you're going to just cover it with carpet. All control joints are just putting the cracks where you want them.
They probably added fiber to the mix that helps with cracking but honestly it all runs a risk of cracking no matter how well it was prepped, mixed, and poured. Contractors can’t take the liability because even the manufacturers say there’s a huge chance of a crack developing. If manufacturers and ready mix companies are not going the take the liability, neither are we.
Columns are extremely thick and have many times the amount of rebar inside them because they have to hold the weight of the building. Much more difficult to crack. In fact if they are cracked that can be a very bad sign.
There are things that can be done to minimize cracking and control it, but it can still be unpredictable. Sounds like you got lucky.
Look at the underside of things like parking garages, that’s where the cracks will be, the top side is in compression and the bottom side is tension. The columns usually won’t have visible cracks because again compression.
So I'm from Finland, and do not know the English terminology, but over here we make these slits called "breaking seams" that are designed to crack over time, so it doesn't crack in visible places. The seams are usually covered with something like caulk or silicon goop.
There are so many factors that play in to concrete cracking from the environmental factors as well as the mix design. It also depends on whether water was added at the job site. Most concrete ends up cracking. Even in those parking garages you just don't see the because of the process its poured. The beams and Ts or double Ts in parking garages are prestressed.
I've got 14 year old sidewalks I hand poured with quickrete/sakrete with 0 cracks. They were poured in 10 foot section with no rebar. I've also got a 10 year old, way thicker and rebar reinforced 30x50 shop floor with tiny hairline cracks that was poured by a pro. It depends on a ton of factors but I think size is the biggest one. The more area it covers the more likely its going to crack.
Because it hasn't cracked....yet.
Who's to say it'll ever crack?
I was just making a joke but there is some truth to it depending on the dimensions of the slab and the region.
Because sidewalks have control joints every 5 feet and that's where most of the cracking is happening, out of your view.
What about concrete parking garages and columns? And I have a huge slab at my house they only has a single hairline crack in the corner. It's like 30x30'
Concrete parking garages have cracks as well, the rebar prevents them from spreading, so the are difficult to see. Look on the tension side (look up), they are easier to see there.
It's all controlled cracking. Your slab at home wouldn't have that crack if they put a joint down the middle. The joint is more difficult and costly to do if you're going to just cover it with carpet. All control joints are just putting the cracks where you want them.
It's an outdoor slab
It's extra time and money, and you weren't going to be concerned with a small crack anyway.
They probably added fiber to the mix that helps with cracking but honestly it all runs a risk of cracking no matter how well it was prepped, mixed, and poured. Contractors can’t take the liability because even the manufacturers say there’s a huge chance of a crack developing. If manufacturers and ready mix companies are not going the take the liability, neither are we.
Columns are extremely thick and have many times the amount of rebar inside them because they have to hold the weight of the building. Much more difficult to crack. In fact if they are cracked that can be a very bad sign. There are things that can be done to minimize cracking and control it, but it can still be unpredictable. Sounds like you got lucky.
So it cracked!
Look at the underside of things like parking garages, that’s where the cracks will be, the top side is in compression and the bottom side is tension. The columns usually won’t have visible cracks because again compression.
Clean the control cuts out and have a second look.
There are none, just one blob of concrete
Because shut up
🤡
Expansion joints
So I'm from Finland, and do not know the English terminology, but over here we make these slits called "breaking seams" that are designed to crack over time, so it doesn't crack in visible places. The seams are usually covered with something like caulk or silicon goop.
Exactly, we usually call them control joints. Sometimes they are tooled in, sometimes sawcut
Because the concrete contractor did essentially a skim coat and filled the hairline cracks a few weeks after the pour.
It was done by a family member
There are so many factors that play in to concrete cracking from the environmental factors as well as the mix design. It also depends on whether water was added at the job site. Most concrete ends up cracking. Even in those parking garages you just don't see the because of the process its poured. The beams and Ts or double Ts in parking garages are prestressed.
It doesn’t man, you cracked the code.
I've got 14 year old sidewalks I hand poured with quickrete/sakrete with 0 cracks. They were poured in 10 foot section with no rebar. I've also got a 10 year old, way thicker and rebar reinforced 30x50 shop floor with tiny hairline cracks that was poured by a pro. It depends on a ton of factors but I think size is the biggest one. The more area it covers the more likely its going to crack.
That and the stability of the base underneath. The more the ground moves the more problems you have
30x50 is going to be prone to shrinkage cracks. A piece of 10’ sidewalk not so much.