Concrete Cylinder breaks
Concrete Cylinder breaks
(OP)
If you have the compression strength of 4000 psi or greater in your cylinder test breaks.
What are the long-term effects with not having any aggregate fractures (bond failure); cylinders with lateral and Hort. shears and no concrete stink to the rebar (rebar can be washed clean with minimum to no effort)? Need some second opinions.
What are the long-term effects with not having any aggregate fractures (bond failure); cylinders with lateral and Hort. shears and no concrete stink to the rebar (rebar can be washed clean with minimum to no effort)? Need some second opinions.





RE: Concrete Cylinder breaks
RE: Concrete Cylinder breaks
RE: Concrete Cylinder breaks
is the aggregrate crushed or is it rounded/smooth gravel? Was it inspected prior to the construction? Was there any inspection of the steel before the pour? Is there any sign of oil or paint on the steel?
RE: Concrete Cylinder breaks
The aggregrate is round/smooth 3/4 and smaller. Yes, we made a trip to the batch plant and looked at the stock pile of gravel before pours started. All seemed ok. The rebar was inspected and no sign of any oil or paint was present. Are plan once we resume pouring is to have field cured cylinders along with lab cured.
RE: Concrete Cylinder breaks
The horizontal shear of the test cylinders show that the compression testing apparatus may by off-kilter or something wrong with capping compound materials or procedure.
As for the rebar, as long as there is not alot of rust or another compound on the rebar, I would not see a problem.
RE: Concrete Cylinder breaks
Bad "breaks" occur when the testing machine is out of tolerance (usually if the upper or lower bearing blocks are not planar), if the technician puts the sample in off center (eccentric loading), if the cap has not gained full strength, if the cylinder top and bottom are not within plane tolerances,.....and so on.
RE: Concrete Cylinder breaks
We should remember Mohr's diagrams? How can the shear plane be horizontally planar? Doesn't make sense.
You can make the cylinder break a bit higher by jacking up the rate of loading (but not if you are following the set rate of loading requirements). Another point - cylinders (and the breaking thereof) has really "nothing to do" with the strength of the concrete in place.
RE: Concrete Cylinder breaks
Horizontal break planes are usually a result of a cylinder anomaly like you described.
RE: Concrete Cylinder breaks
To paraphrase Ron (I think) from an earlier thread: The purpose of taking cylinder specimens under standardized procedures, curing them under standardized procedures, and testing them under standardized procedures is to see what the MIX DESIGN is capable of doing. The cylinders represent the mix design. If the mix design is capable of producing concrete of a certain strength, then by inference it is OK in place from a design perspective (that's f'c).
RE: Concrete Cylinder breaks
RE: Concrete Cylinder breaks
http://www.mastrad.com/slump.htm
RE: Concrete Cylinder breaks
Based on your postings, I would also guess that when you were sampling concrete on a regular basis your slump cone and plate would last for years. Am I right?
RE: Concrete Cylinder breaks
And DO NOT even get me started on the condition of tech's equipment. Why does concrete harden on the inside of a tech's slump come in 2 weeks but not on the inside of mine is 10 years!? Don't know. It's a dang mystery is what it is.
But anyway...
I have a question along these lines but it really needs another thread so I'll start it over in concrete....