Sometimes it is due the owner not doing proper maintenance. Everything requires maintenance. Or not using the proper material for the environment it is in.
ie. A plaster product will not ever stand up to outdoor environment. or a concrete item cannot be allowed to hold water during freezing weather. (It will crack)
A car engine must have the proper amount and type of oil or it will fail.
No of these are a result of a failure of the materials....they are a failure of the human to do proper maintenance.
Of course a human can screw up the mix. But unless the cement company was adding fly ash in place of portland. And any company doing that will not remain in business long. As contractors will not use their junk.
The person pouring the cement can look at the ready-mix load and can see that the mix is wrong. You can see the gravel (size and amount) you can see if the sand is the is too small. And so will the city building code inspector.
Construction cement mix is strong. But as I said concrete cannot standup to water freezing. Concrete is porous and the cement absorbs water and when it freezes and expands...it will crack and pit the concrete. Items that hold water are more at risk from freeze cracks.
If the ground underneath a wall, or flatwork (floor, sidewalk, patio, etc) moves that concrete will crack or break all together.
And this is not failure of the cement mix or material....this is what concrete does. Rebar will NOT stop it. In fact too much or too large rebar will cause it. The rebar is there because the concrete is going to crack when it meets these situations.
This post was edited by my2cents at July 29, 2021 4:57 PM MDT
A crack in a building or bridge ....a crack in the soul of a homo sap. Now a crack in a seed is something new to me. As I ponder upon it I am trying to see what relevance it has to my question. Because you bury them I have never seen a seed crack upon from which life springs in a vegetable or fruit or flower. I would like to see what it looks like. Now an egg cracks and a baby chick come out. It takes life to crack that shell. Life doesn't begin with the crack in the instance. A living thing is the cause of the crack. In any case wherever the crack it doesn't strengthen anything does it? A crack in a relationship can be the beginning of the end not the end. You step over a crack in the pavement as a kid because you don't want t break your mother's back. I did it. Did you? Thank you for your reply Walt and Happy Thursday to thee and thine. Variations on a crack. A crack riff. Ever track a crack? Or crack a track? But I digress! :)
my2cents 