Why consolidatate fresh concrete?
Why consolidatate fresh concrete?
(OP)
I'm bracing myself for the impending flood of responses to this question.... The importance of consolidation using a vibrator just doesn't seem intuitive to me.
I am aware that consolidation of fresh concrete is as common at a concrete pour as the presence of forms or reinforcing steel, and that the contractor should be doing so if the specs tell them to. What's the difference in fresh concrete that has, for example, a sand grain at a certain location from that where the same grain has sunk a cm or so lower? And if the concrete is poured at, say, a 5 inch slump per approved specs, it seems to me it should be wet enought to saturate the re-bar to securely form the bond.
Is there any documentation that could help me strengthen my gumption on the subject?
I am aware that consolidation of fresh concrete is as common at a concrete pour as the presence of forms or reinforcing steel, and that the contractor should be doing so if the specs tell them to. What's the difference in fresh concrete that has, for example, a sand grain at a certain location from that where the same grain has sunk a cm or so lower? And if the concrete is poured at, say, a 5 inch slump per approved specs, it seems to me it should be wet enought to saturate the re-bar to securely form the bond.
Is there any documentation that could help me strengthen my gumption on the subject?





RE: Why consolidatate fresh concrete?
In general, Concrete can and will trap air that causes voids. These voids allow stress to develop in a concentrated area causing local weakness. Bad in beams worse in columns.
Also the vibration of the concrete adds 'energy' to the mix that 'helps' it flow over and around reinforcing steel and into the corners of form work.
RE: Why consolidatate fresh concrete?
And yes, a very high slump workable concrete will eliminate the need for compaction which is a different type of concrete called self-compacting concrete which is very different in use and composition of the conventional concrete pored at sites (lower aggregate max. size, higher content of fine materials, higher cement content and especial viscosity agents) this type mof concrete will self compact and level when pored.
Try these:
http://www.ce.memphis.edu/1101/notes/concrete/everything%20about%20concrete/9_-_handling.html
http://155.217.58.58/cgi-bin/atdl.dll/fm/5-428/ch5.htm#s7p4
http://www.portcement.org/cb/concretebasics_placing.asp
More details??????????
A. Sadi
www.geocities.com/concretesite
RE: Why consolidatate fresh concrete?