cracks in concrete wall: what is the reson for it?
cracks in concrete wall: what is the reson for it?
(OP)
Hi
we spoka about cracks in plaster already. The answers were very clear for the introduced crack patern
now what is the reason when you have the same patern of crack in a reinforced concrete wall?
see attachment
this can#t be shrinkage because it is reinforced Y12 every 200mm each face horizontal and vertical


we spoka about cracks in plaster already. The answers were very clear for the introduced crack patern
now what is the reason when you have the same patern of crack in a reinforced concrete wall?
see attachment
this can#t be shrinkage because it is reinforced Y12 every 200mm each face horizontal and vertical






RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
BA
RE: cracks in concrete wall: what is the reson for it?
But how wrong can you mix the concrete to get it so bad? Then the mix was totaly toltaly out of any propotions but the colour still looks ok.
so you are saying definately to much water?
I thought maybe I shouldn´t have fixed the wall panel (7.0m) on the sides to the columns so that the pannel could still move or shrinke a bit
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
There are a great deal of other manuals which puport to help identify cracks in service, some with detailed commentary as to possible causes, but I've never found them to be anywhere near as good as the freely available BIM (free and available if you're Canadian at least).
RE: cracks in concrete wall: what is the reson for it?
I was also looking for the Aligator cracks but it seams like they use this word only for asphalt and roads but nor really by concrete walls
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
No, this is not an issue of too much cement. It is an issue of poor mix control which, likely, is a high water-cement ratio as CEL noted. It could also relate to poor gradation, also pointed out by CEL. You noted variable mix control but state that the color looked ok. Good and bad concrete can both be some variation of a gray color. Means nothing.
If you are designing reinforced concrete I would suggest that you learn a bit more about concrete technology. You need to know definitively when you have bad concrete.
As another observation, your columns look a bit small for the surrounding structure. Just a casual observation.
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
Well said!
RE: cracks in concrete wall: what is the reson for it?
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
Before someone spouts the industry's propaganda, NO it is not okay to add salt because eventually most concrete is cold weather climates is salt saturated from deicing. That happens later, takes time to permeate, and linseed as well as other treatments can do a great deal to slow such penetration. Salt in the mix is just asking for long term durability issues.
RE: cracks in concrete wall: what is the reson for it?
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: cracks in concrete wall: what is the reson for it?
I wish there were a simple site test. I've been looking, but to no avail. I heard that you could do something with pool testing kits, but I don't buy it.
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
thank you fro the valuable tips.
The comment reagrding the columns: The columns just next to the cracked wall are only supporting a roof. Nothing much so even they sizes is far overdesign as it is
@ Hokie: this is quite interesting what you observe here "the vertical cracks are restraint shrinkage cracking. The slab was cast first, then the upstands, and the restraint of the slab caused tension in the newly cast " but somehow I can´t understnad exactly why the slab woudl trigger this vertical cracks? I woudl understand the vertical column next to the wall much more but the slab is restreining the wall?
RE: cracks in concrete wall: what is the reson for it?
And this: Link
When the plastic, second pour concrete tries to shrink, the hardened, first pour restrains that shrinkage. I got burned on this in the past when having a new curb installed over an existing composite deck system. I provided standard T&S reinforcing and it cracked like nobody's business. 0.2% temperature and shrinkage reinforcing is really only appropriate for "free shrinkage". For restrained conditions, I've been told that 0.4% is better.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: cracks in concrete wall: what is the reson for it?
RE: cracks in concrete wall: what is the reson for it?
KootK has explained it. The picture in his first link of cracking in a wall just above a footing shows what happens. I like to put some extra reinforcement there to control those cracks better. The cracks will probably still form, at roughly 3 metre centres, but will be smaller as the reinforcement increases. These cracks may not be structurally significant, depending on the exposure, but may still be undesirable aesthetically.
RE: cracks in concrete wall: what is the reson for it?
I'm starting to wonder if the intent all along was to give a nod to shrinkage restraint.
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.