About Reinforced Concrete Column Casting
About Reinforced Concrete Column Casting
(OP)
Hello,
In rcc column casting how many times we can casting each column?
Say can we casting a 12' column or 10' column in 3-4 times?Which precaution we may follow in this situation?
if f'c=3 ksi ,fy=60 ksi
Sorry for my bad english.
In rcc column casting how many times we can casting each column?
Say can we casting a 12' column or 10' column in 3-4 times?Which precaution we may follow in this situation?
if f'c=3 ksi ,fy=60 ksi
Sorry for my bad english.
RIFAT






RE: About Reinforced Concrete Column Casting
Are you asking how many times a column form can be re-used?
RE: About Reinforced Concrete Column Casting
RE: About Reinforced Concrete Column Casting
RIFAT
RE: About Reinforced Concrete Column Casting
All that said, I would expect the contractor to have a valid reason for using multiple pours. You know, a reason other than lousy quality control. In my opinion, multiple pours does impact the quality of the finished product to a degree. Consider:
1) There will often be slight angular change in the column and/or rebar at the joint that was probably not accounted for in design.
2) At every joint, you develop some local restraint stresses where the shrinkage of the new concrete is retrained by the presence of the old.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: About Reinforced Concrete Column Casting
RIFAT
RE: About Reinforced Concrete Column Casting
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: About Reinforced Concrete Column Casting
Pour the concrete "slowly", to keep pressure low, and it takes "forever" to place a small concrete volume.
Have many columns ready for "slow" placement in each one, and Contractor needs lots of forms. Also, the placement crew has to move placement operations between forms on a planned, uninterrupted, regular schedule.
As a bridge Contractor, we opted for fast placement of cylindrical columns (36" diameter) using steel forms. Of course circular forms are the optimum shape for high internal pressure. If columns are any other shape (say square or rectangular) then form design detail become even more important to effectively resist the concrete pressure (both for strength and without excessive form deflection).
Even with all factor being favorable (steel circular forms) the practical limit for fast placement of a single lift is essentially 20 feet height (hydrostatic pressure of 3000 lb/ft2 at the bottom of the quickly filled forms).
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