[TowerTalk] Newbee concrete rebar questions

[Tom Anderson]

All:

When I put in the base for my TriEx W51 crank up back in 1993 I used the same size rebar the base was made of by TriEx.  I forgot the exact size, but it was the same diameter just in 3 ft sections I found at a home improvement store.  They fit well within the base which is approx 4x4x6.

To attach it to the base I used the same twist wire that they use on interstate and state highway rebar and twisted it with a pair of lineman's pliers until the short piece was snug against the base pieces.

A friend of mine WB5IUU had a wooden "mold" support for the base that he had made for his W51 years before and we just sat the whole base on that for support before pouring the concrete.  The concrete sits up about 3-4 inches above ground to keep water from my yard collecting on the concrete.  

Next, we used what some in the concrete trade called a six sack mix, supposedly the same slump and mixture as used on interstate highway bridges.  We bought the concrete from a concrete co. who brought their truck and pump and forced the mixture about 75 feet into the backyard and into the hole.

After filling the hole and mold, we smoothed it out and then sprayed water lightly on it for about a week to keep the concrete cool while it was curing.  I didn't attach the tower to the base until about a month later when everything seemed fairly dry, although they say it can take months for a slab that size to fully cure.  

Some 17 years later the tower is still attached to the base and the concrete.  Nary a problem with it in that time, not even a crack anywhere I can see. The base has supported the fully extended tower through some 60-70 mph winds in the Dallas-Fort Worth area with nary a problem, when I couldn't get home to crank it down.

Tom, WW5L