[TowerTalk] Rebar schedule

[Jim Lux]

On 5/4/12 4:33 AM, Don Bowen wrote:
> On 5/4/2012 3:07 AM, John Lemay wrote:
>>
>> Hi Don

>> Not enough information !
>> How tall is the mast
>
> To the top of the fourth section is thirty six feet.
>
>> Will it be guyed or freestanding ?
>>
> Free standing
>> What will you put on top ?

> hy-gain TH-3JRS triband and a Yeasu G-450A rotator.

>> What soil do you have 3ft down ?
>>
>
> Gravel, rocks, clay.
>

"I was told I should have at least a yard of concrete in the base.  With
the base spread and the frost line here I think the base will be 48"
square by 30" deep.  What I want to know is this a good size and how
much rebar should I have in the base."

SHort of getting an Engineer to design something or finding the 
manufacturer's recommended base; Look at other freestanding towers of 
similar height and load capacity and see what they recommend for the base.

looking at the Trylon Titan in that sort of height class and able to 
hold 5-6 square feet in 85 mi/hr winds, it looks like the base is going 
to be more like a 5x5x5 foot cube of concrete..  more like 5 yards of 
concrete, just a bit more than the "at Least a yard" you were told<grin>.

What wind zone are you in? (that makes a big difference)
Are you willing to have it collapse or fall over?  (if it's going to be 
out in the middle of a field where if it falls down, nothing gets hurt, 
you can be a bit more sketchy)