What is the acceptable maximum slump for column considering congested rebars and workability?
What is the acceptable maximum slump for column considering congested rebars and workability?
(OP)
I have columns with congested rebars and tie bars. I'm planning to order a ready mix concrete with slump of 125 +/- 25mm. Our mix design is 35 MPa with max aggregate nominal size of 19mm with water-cement ratio of 0.42. What is the acceptable max slump for column? Please any expert on concrete to give your suggestions. Thank you





RE: What is the acceptable maximum slump for column considering congested rebars and workability?
Assuming you have a clear spacing between all that is about 60mm or more, then your slump range and aggregate size are reasonable, assuming you can get internal vibration (vibrating the form itself or the rebar causes problems, so don't do that. If your spacing is less, then reduce your aggregate size accordingly (but not below 12mm) and increase your slump to 150mm +/- 25mm.
Remember, when you reduce your aggregate size you will need to increase the cement content and the water content to maintain the same w/c ratio.
Use a high quality plasticizer to increase the slump without increasing the mix water.
RE: What is the acceptable maximum slump for column considering congested rebars and workability?
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: What is the acceptable maximum slump for column considering congested rebars and workability?
We use a lot of bar (#10's @ 6" are not unusual in walls) and hold our slumps to 4 to 6 inches.
RE: What is the acceptable maximum slump for column considering congested rebars and workability?