[TowerTalk] Concrete testing

[Jim Thomson]

Date: Thu, 2 Sep 2010 19:01:12 EDT
From: K7LXC at aol.com
Subject: Re: [TowerTalk] Concrete testing
 
In a message dated 9/2/2010 8:46:03 A.M. Pacific Daylight Time,  
towertalk-request at contesting.com writes:

>  Good Lord. Whatever happened top Joe Average Ham and  just pouring 
concrete
for a base? I can see all this if you have an  gigantic hundreds of feet 
high
superstation, but the average guy doesn't  need to have his concrete
analyzed.

>  You dig the hole the  tower manufactuer specifies and you use the 
rebar/cage
they say. You guy  correctly if it is guyed tower. You add concrete and make
sure there aren't  voids. 99.999% of us need nothing more than that.


        I agree 100%! The problem  is that the building department thinks 
that everything constructed is going to  be habitable - not something less 
than 10 yards for another purpose. :-(
 
        Also, I've never seen or  heard of a tower failing because the base 
concrete split fatally. It's always  the steel. (Big base shifting in sand, 
mud, etc. excepted.)
 
        And it's burdensome for an  amateur anything to have to comply with 
this monetarily. What a waste of time,  effort and money - for everyone. 
Just my opinion. I've counseled permit  applicators to protest it.  It might 
work. 

#### Building permits for tower's are exempt  under both the FED
and Provincial rules.  However, my local municipality sez that tower's
must have a building permit.  City hall here  forces hams to hire a PE
and the PE  must inspect and approve the hole/forms/cage... and photograph
it, b4 any concrete can be poured/pumped.   The PE also has to come
back after the tower is installed..to check all anchor rod + leg bolts
for correct torque values.   If the tower snaps 1/2 way up..after the fact..
or snaps off at the base..it's not the PE's  problem.   Every  free standing tower
base, including UST crank ups  is designed to break 1/2  to  2/3 the way up..
so if a failure occurs..it simply folds over... and does not fall full length. 

##  1153 hams here in town.. and only 5 on HF.  Hams go through the same identical
process as a cell co..as of  Jan 1 -2008.  City hall hates ham tower's  with a passion. 
Not only do I have to pay for the PE and building permit... I also have to pay a $500.00 
surety bond...in case the back hoe/dumptruck/line pumps etc... trashes the boulevard. 

##  It doesn't matter what the manufacturer wants.. the local PE  will always tweak it up  a bit.
The  newer HDX-689 tower's  weigh 3250 lbs... with out the  mast/rotor/ants.  I have the older
model, with double walled legs, Z bracing, and also X bracing. Mine weighs 5000 lbs when the
offloading crane fellow put the scale on it.  Stick a 100' tall tower, weighing 5500 lbs with ants
next door to my neighbours brand new $700K  home... and city hall worries abt
lawsuits...and so does the PE.  Years ago, city hall made hams hire a  PE....to tighten every bolt
on every section splice, on any tower.    One old geezer,  1/2 mile from me had to cough up
$850.00 for the PE  to torque every last bolt on his 56' tower.  Big outcry after that.  Now it's
the concrete base they want..'done right'.   My rebar cage got the PE stamp the 1st time.....with the
provisio that I close off the top with a grid  of bars... and add a 2nd grid  down 4.5'.     The PE  also
came back  a 2nd time to inspect the 12 x anchors rods... and also checked to see if I had  added
the required extra rebar.  It was then stamped a 2nd time.   It will require a 3rd stamp when he 
checks the  12 x anchor bolts and  18 x leg bolts.  This bozo charges $150.00 per hr... PLUS $75.00
per hr for driving time.  The cage got inspected twice..instead of once..since he didn't like it..and
wanted more rebar.  Rebar + more concrete is a lot cheaper than having the PE keep coming out. 
He wants it built so he doesn't get sued..and ditto with  city hall.  It's all political.  They want
tower bases  seismic rated as well..hence the 60 ksi bars and large stirrups in the corner..and stronger
concrete. . 

##  City hall could easily demand that any ham tower meet  Canadian  S-37 specs... [25mm of 
ice on all surfaces, top/bottom, etc.. and super high wind pressures + seismic rated]... in which
case, UST  + Rohn need not apply.  Our eq of the FCC  won't back up hams either..not one bit.
Be glad you don't live in a socialist police state..like Canada.   

later... Jim  VE7RF      







Cheers,
Steve    K7LXC
TOWER TECH