Structural Concrete Slump
Structural Concrete Slump
(OP)
Do you generally specify what range of slump is required for your structural concrete?
If so, what are the ranges you use for different types of construction (i.e. slabs, beams, columns, etc) and what is the reasoning?
If so, what are the ranges you use for different types of construction (i.e. slabs, beams, columns, etc) and what is the reasoning?






RE: Structural Concrete Slump
Also keep in mind, the slump test is really only a measure of the slump of the concrete. It is primarily a tool for measuring the batch to batch consistency and alerting you to the probability that there is something wrong with a batch where the slump is inordinately high or low.
Greg
RE: Structural Concrete Slump
Dick
RE: Structural Concrete Slump
Our general notes specify 80mm for suspended slabs and beams, however 100mm flows better. There can be a loss of strength and increased shrinkage due to higher water content at the higher slumps (which is why we leave it at 80 on our notes), however superplasticizer is often used to increase the 80mm to 120mm (+/-20mm). You can then get good compaction and workability without sacrificing strength.
RE: Structural Concrete Slump
Personally, I belive that a 4 inch slump is an absolute minimum except for certian situations. For most strucures six inch will give you a a better finished product than 4 inches. There was a very lively debate on this issue recently ACI Concrete code issues "Slump Test After Adding Super P" Thread 167-22742