[TowerTalk] Vibrator for 2x2x4 hole?

[gdaught6 at stanford.edu]

On 16 Aug 2007 at 11:56, Gene Smar wrote:

> Dana:
> 
>      For a small hole like that you probably can get away with poking at the 
> concrete with a 2x4 piece of wood as it's being poured.  The goal is to 
> ensure there are no voids or air pockets in the concrete after it sets up, 
> thereby reducing the ultimate strength of the pour.
> 
>      My tower's foundation is made of 10.5 cuyds of concrete so I rented an 
> electric vibrator for the project.  The 2x4 idea would not have been as 
> effective for my project because of the volume of concrete, plus the 
> foundation was undercut around the bottom edges and I wanted to make sure 
> that that space was filled with mud.

When my base was poured (by a concrete professional) it was actually 
pumped.  The guy said that if you have the concrete mix correct and 
the flow rate right, you can get a "standing wave" of the mix going 
in that virtually assured that there would be no voids.  No vibrating 
necessary.  I watched as he did it, and it was slick!  Once he got 
the hose flowing, it took 90 seconds to fill the hole it took me over 
a week to dig!  [2.3 cu. yds.]

73,

George T. Daughters, K6GT