Plastic welding with steel wool

Tips, tricks, questions and answers to tech questions
demographic
Posts: 3068
Joined: Mon Mar 16, 2020 9:30 pm
Location: Less that 50 miles away from Moscow, but which one?
Has thanked: 1361 times
Been thanked: 1749 times

Re: Plastic welding with steel wool

Post by demographic »

On about concrete, if you look at a concrete lintel its got the steel re-bar in the bottom where its under tension, which means it holds it so the top (all concrete bit) is under compression during usage.

Some concrete also has fibres mixed in which lessens cracks propagation as well as the reinforcing bars that it usually has.
User avatar
Yorick
Posts: 16801
Joined: Sat Mar 14, 2020 8:20 pm
Location: Paradise
Has thanked: 10336 times
Been thanked: 6915 times

Re: Plastic welding with steel wool

Post by Yorick »

demographic wrote: Wed Jul 26, 2023 7:56 pm On about concrete, if you look at a concrete lintel its got the steel re-bar in the bottom where its under tension, which means it holds it so the top (all concrete bit) is under compression during usage.

Some concrete also has fibres mixed in which lessens cracks propagation as well as the reinforcing bars that it usually has.
Don't let the Internet experts grind you down. What do you know ? ;)
Mr. Dazzle
Posts: 14068
Joined: Mon Mar 16, 2020 7:57 pm
Location: Milton Keynes
Has thanked: 2572 times
Been thanked: 6300 times

Re: Plastic welding with steel wool

Post by Mr. Dazzle »

demographic wrote: Wed Jul 26, 2023 7:56 pm Some concrete also has fibres mixed in which lessens cracks propagation as well as the reinforcing bars that it usually has.
Yaaknooow....now that you say that, I do wonder if the CFRP reinforced concrete bridges here in MK actually have carbon fibres in the matrix, so in the cement that is. It would make some sense 'cause you'd wanna warn people of that fact before they tried working on it with 'normal' concrete methods :think: Maybe that's what the signs are about.

Re: Lintels...I've recently had a pizza oven come BBQ stand built in my garden out of bricks and lintels. The lintels have steel bars right in the middle, rather than off to one side as you say and as I expected. Wassat about then? Is it just so you can't put them in upside down by mistake?
User avatar
Rockburner
Posts: 4404
Joined: Sun Mar 15, 2020 11:06 am
Location: Hiding in your blind spot
Has thanked: 7852 times
Been thanked: 2555 times

Re: Plastic welding with steel wool

Post by Rockburner »

Mr. Dazzle wrote: Wed Jul 26, 2023 9:08 pm Wassat about then? Is it just so you can't put them in upside down by mistake?
That would be my guess. You can guarantee that any "This way down" signage/notices on the lintel would end up pointing in every direction except down.
non quod, sed quomodo