overcutting corners in an opening
overcutting corners in an opening
(OP)
I am a concrete cutting professional and I have been wondering about the strength of cut openings. Specifically, is there a structural / strength difference between a square cut corner and a overcut corner. Are there any codes that specify this?
I am asking because of the growing job requirements for square corners (with NO overcut).
Thanks,
isocutter
isoworks@home.com
I am asking because of the growing job requirements for square corners (with NO overcut).
Thanks,
isocutter
isoworks@home.com





RE: overcutting corners in an opening
Carl Bauer CEng MICE
Bauer Consult
PO BOX 2224
Gaborone
Botswana
RE: overcutting corners in an opening
If no overcutting is specified, then you should price the work based on providing the extra labour, and discuss this with the engineer after you have the job.
Reinforcing steel can be located within the slab with a good quality stud detector or device made for this purpose and depending on the hole size and location it may be possible to reduce the number of bars cut. If no additional bars are cut, the engineer may be amenable to accepting this.
With post-tensioned stuff, usually specify that the tendons be located and that a chipping hammer be used in proximity.
In occupied spaces, often see contractors cut square holes using a circular coring drill; this approach tends to be less messy and dusty than using saws.
I've also seen coring drills used for the corners and the edges sawn; this provides a smooth corner and reduces any stress riser.
RE: overcutting corners in an opening
In addition, the overcuts may damage reinforcing bars which extend just beyond the opening edge, further reducing the wall/slab strength.
RE: overcutting corners in an opening
It seems that the several of you that have responded are in agreement that the corner would stronger with no overcutting.
Does anyone know of any codes that exist that specify square corners or is it just up to each engineer?
Thanks again.
isocutter
isoworks@home.com
RE: overcutting corners in an opening